Which question about whale sharks is nonscientific?
what do whale sharks eat?
how big is the average whale shark’s mouth?
does a whale shark like having a large mouth?
what happens to the water that enters a whale shark’s mouth?

The correct answer is C. Does a whale shark like having a large mouth?

Explanation:

Scientific questions always focus on phenomena that can be tested and measured. Due to this, questions that involve personal perceptions, opinions, perspective or similar are nonscientific.

According to this, questions such as "What do whale sharks eat?" or "How big is the average whale shark’s mouth?" are scientific because these can be answered through experiments, observations and measures as you can observe the type of things whale sharks eat and you can measure their mouths. However, "Does a whale shark like having a large mouth?" is nonscientific because this focuses on a personal perspective; also, it is not possible to test or measure the opinion of whale sharks about their mouth.