Is the following statement a good definition? why?

a cat is an animal with whiskers.

(a). it is not. the statement is not precise.
(b). it is not, the statement is not reversible.
(c). it is because all cats have whiskers.
(d). it is. the statement is precise and reversible.

“you meet new people on a job. kayla morrison says, 'i work with two college students from the east coast, and it's been interesting learning about their lives.' kayla has also come to think of the café owner as a mentor who is providing her with valuable information about the food service industry. kayla is even thinking about applying for the culinary arts program at her high school.” what is the topic sentence of this paragraph?