This sentence's error is a discrepancy in number. Two children are mentioned, "Jordan and Marvin," so logically, they would grow up to become two different lawyers. The sentence uses the singular noun "a lawyer" where it should use the plural noun "lawyers," so "lawyer" is the correct answer.

The corrected sentence reads, "Jordan and Marvin’s mother has decided that they will become lawyers when they grow up, but they seem more artistically inclined."

This sentence's error is a problem with agreement of plurals. Multiple "caterpillars" should form multiple cocoons, but the sentence uses the singular noun "a cocoon," which doesn't make sense. "A cocoon" is thus the correct answer, and the corrected sentence reads, "As part of their development, caterpillars form cocoons and eventually emerge as moths or butterflies."

As with pronouns, when a noun or group of nouns is replaced in a sentence by another noun, they must agree in number. The multiple subjects "Dedication," "work," and "attention" call for a plural word.  A simple correction would be "important factors"

In this sentence, there are two individuals, both painters, so the object should reflect that number. The corrected sentence reads, "Frida Kahlo and her husband Diego Rivera were both well-known and talented Mexican painters."

This sentence lacks agreement between nouns. Since there are many aliens, “savior” should be plural. The corrected sentence reads, "Recognizing that the inhabitants of Earth suffered from many wars, disasters, and diseases, the aliens hoped to be welcomed as saviors."

Because there are multiple sisters, the noun that describes their profession ("pediatrician") should be plural; "a pediatrician" should thus be changed to "pediatricians."

The correct answer is "a member." Because Alyssa is asking "her friends," which is plural, the corresponding noun should also be plural—"members" instead of "member."

Since the sentence uses a compound subject—"Elena, Laura, and May" —the corresponding noun of "ticket" should be plural, since the three girls will need multiple tickets.

Because the plural "ideas" and the singular "a dream" have the same referent, both should be either singular or plural. Therefore, the best way to correct this sentence is to pluralize "a harmless notion."

"All of the" is inconsistent with the rest of that sentence, specifically "an excellent producer." These two nouns must agree in number, but they do not here. "All" should be changed to "Each" in order to maintain agreement with "an excellent producer," and the corrected sentence would read: "Each of the farmer's chickens proved to be an excellent producer..."