When something is "contrived," it is obviously artificial or obviously fake. So, "artificial," which means fake or man-made instead of natural, is the correct answer.

"Ludicrous" is an adjective that means "so foolish, unreasonable, or out of place as to be amusing; ridiculous." So, we need to pick out an answer choice that means something like "ridiculous." "Sensible" cannot be the correct answer, then, because "sensible" is an antonym of "ridiculous." "Preposterous," however, is an adjective that means "contrary to reason or common sense; utterly absurd or ridiculous," and because it is the answer choice that is closest in meaning to "ludicrous," "preposterous" is the correct answer.

The word "evident" is an adjective that means clear or obvious. For example, if a certain fact is evident, it is so clear-cut that most people likely know it to be true. "Obvious" is our answer here. "Obscured" means hidden, and "confusing" is the opposite of "obvious," so we can eliminate those choices right away. "Healthy" refers to a behavior or lifestyle that is good for your body or mind, so that choice is irrelevant here.

When someone is "oblivious," he or she is totally unaware of something. For instance, we could say, "John was totally oblivious to the fact that his mother was standing right behind him." This means that he didn't know she was there at all! While you might be tempted to think that "unintelligent" is a good synonym for this, the best option is actually "unaware"—as should be obvious, given what is the meaning of "oblivious."

When something is "obvious," it doesn't take much work to discover it. For example, your friend might look out the window and say, "There is a world out there." Perhaps, the same friend could tell you, "The leaves are on the outside of the tree." In both of these cases, you can say, "That's obvious!" Thus, we can say that a synonym for "obvious" is "clear." We do use "clear" to describe something that does not need to be explained. Think of when your teacher or parent asks, "Am I clear about this?"  He or she means, "Do you understand me completely?  Is my point now totally obvious?"

The word "enlightening" comes from the word light, but it is used in a metaphorical sense. It means making something understandable. Think of when we say, "That was an enlightening explanation."It is like the explanation "shines" and makes its topic obvious. The best option for this is "informative," for informative things or actions help to explain something else.

When someone is "ignorant," he or she does not know something. Thus, we can be "ignorant" of someone's name, meaning that we do not know it. Now, when we just say that someone is "ignorant" without any particular reason or explanation, we mean to say that the person is rather ill-informed. He or she is ignorant of things that he or she should know. Therefore, the best option that we have here is "uninformed." This can apply to both senses. None of the other options really express this idea of not knowing something.

When something is "planned out," we actively make sure that we think through the steps involved. "Intentional activity" is this kind of planned activity. Maybe you have heard something like, "He unintentionally bumped into the old man." This means that the person bumped into the old man without planning to do so. To do something intentionally is to plan it out before executing it.

Fiction is a particular kind of literature.  A fictional story is one that is made up.  This could be a novel or just a short story.  However, what is true of all fiction is that it doesn't repeat facts about reality.   That kind of writing is non-fiction!  The word "fiction" comes from the Latin "to make."   Thus, the best option for "fictional" is "imaginary."