Which of these questions is a scientific question?

Are you happy with your new dress?

How long does it take for bread dough to ferment?

Is it OK to sleep when your sibling is studying?

Is it rude to look away when you see your friend?

How long does it take for bread dough to ferment?

Answer: How long does it take for bread dough to ferment?

Explanation:

A scientific question is a kind of scientific inquiry which can be answered by observatory evidences and the evidences obtain from the experimental procedures. Asking a scientific question is a part of scientific method. That involves making an observation, asking a question on the basis of observation, formation of a hypothesis, testing the hypothesis on the basis of experimentation procedures.

The quality of a scientific question is that it should be testable and answerable by experimental procedures.

How long does it take for bread dough to ferment? is a scientific question this is because of the fact that the time and exact period for the process of bread dough fermentation can be recorded by experimental procedures.