Final answer:
Option a) doubt, remember, imagine is the line with only non-continuous (stative) verbs as they describe states of being or mental processes.
Step-by-step explanation:
The student's question involves identifying a line with only non-continuous (stative) verbs. The correct answer is: a) doubt, remember, imagine. These verbs describe states of being or mental processes, rather than actions or processes which can be considered to continue over time. Verbs like 'sit', 'jump', or 'paint' describe actions, and so they are not purely stative verbs. Whereas 'smell' and 'sound' can be both stative and dynamic depending on context, but since they are paired with action verbs in the choices, option a) is the only line with exclusively stative verbs.