1. choose the sentence in which the verb is a linking verb. a. he works at a gas station. b. his boss pays him well. c. he has walked to work from his house. d. his hours are long and busy.

D-His hours are long and busy. This is the sentence in which the verb is a linking verb. See the underlined word. " To be" is the verb. This is a linking verb because it links or connects the subject: His hours with the adjectives from the predicate: long and busy. The verb "to be" has no meaning by itself. If we put a question to the sentence to get " to be " as an answer, we will ask: What are his hours like?. The answer will not focus on " to be" but on " His hours".  Compare with the following:

A- He works at a gas station. The verb " to work" has meaning by itself. We can ask a question to get " works" as an What does he do at the gas station? Therefore, "To work" does not link parts of the sentence , it just tells what a person does. It is a dynamic verb performed by a pesron.

B. His boss pays him well. "To pay" has its own meaning and it can be the answer to: What does his boss do to him? A person pays to somebody. This is also a dynamic verb performed by people.

C. He has walked  to work from his house. " To walk" is also a dynamic verb; it has got meaning by itself and  it can be the answer to: How has he got to work from his house?

a question like this requires the excerpt to be included in order to answer the question.

answer: a mother fears that the poor lighting poses a danger to the children who play there.