With the sentence phrased the way it is, the thing that is "caring for a pet" appears to be "responsibility." This dangling modifier needs to be changed to make it clear that "children" are "caring for a pet." The correct answer choice is "Responsibility is something children can learn by caring for a pet."

While the singular verb "was" is next to the singular noun "organization," the subject of the sentence is the plural noun "bylaws." This means that the verb "was" needs to be changed to a plural form; therefore, "The new bylaws of the organization were" is the correct answer choice.

The use of the verb "seeming" in the sentence makes the sentence incomplete. As "seeming" is a gerund, or a verb form that functions as a noun, there is actually no verb in the sentence. The correct answer is "seemed to get worse over time."

The original text contains a pronoun agreement error. The possessive pronoun "their" is plural, but it is intended to refer to the singular noun "individual." We must use singular possessive pronouns instead, such as "his or her."

Only answer choices "depends on his or her weight, height, and how old they are" and "depends on his or her weight, height, and age" correctly use "his or her" instead of "their," but answer choice "depends on his or her weight, height, and how old they are" does not use correct parallel structure. Therefore, the answer choice "depends on his or her weight, height, and age" is correct.

The answer choice "the distance between the sun and the planets varies over time" is correct. It correctly uses a singular verb—"varies"—to match the singular subject, "distance."

All of the other answer choices are incorrect because they contain a subject-verb number agreement error. They use plural verb forms when they should use singular verb forms instead.

With the sentence phrased the way it is, the thing that is "caring for a pet" appears to be "responsibility." This dangling modifier needs to be changed to make it clear that "children" are "caring for a pet." The correct answer choice is "Responsibility is something children can learn by caring for a pet."

The underlined phrase has a problem with the phrase "most learning." The phrase is describing the word "scholars." While the scholars might have "the most learning," this would make them "the most learned." The correct answer is "even the most learned of scholars."

The original text contains a pronoun agreement error. The possessive pronoun "their" is plural, but it is intended to refer to the singular noun "individual." We must use singular possessive pronouns instead, such as "his or her."

Only answer choices "depends on his or her weight, height, and how old they are" and "depends on his or her weight, height, and age" correctly use "his or her" instead of "their," but answer choice "depends on his or her weight, height, and how old they are" does not use correct parallel structure. Therefore, the answer choice "depends on his or her weight, height, and age" is correct.

The use of the verb "seeming" in the sentence makes the sentence incomplete. As "seeming" is a gerund, or a verb form that functions as a noun, there is actually no verb in the sentence. The correct answer is "seemed to get worse over time."

When a sentence begins with a dangling participle or descriptive phrase, the person or thing described in that phrase (in this case, "Neil") must immediately follow it. Only one answer choice does this correctly. The answer choice that begins "Neil's anxiety" may appear to do so, but it does not, because the possessive "Neil's" is no longer the subject, but is describing the anxiety.