Atestable hypothesis could be formed from which question?
are bass more active in the daytime than at night?
when whales jump out of water, are they happy?
are red tulips prettier than tulips of other colors?
why are gerbils more popular as pets than hamsters are?

The correct answer is A. Are bass more active in the daytime than at night?

Explanation:

A testable hypothesis refers to a possible explanation or guess about a phenomenon that can be proven as valid or invalid through experiments or tests. Due to this, a testable hypothesis should emerge from questions that focus on a specific natural phenomenon; moreover, the phenomenon studied should be measurable and objective, due to this, aspects such as opinions, feelings or perspectives are not recommended.

According to this, the question that can be used to form a testable hypothesis is "Are bass more active in the daytime than at night?" because this focuses on a phenomenon that is measurable and objective as you can measure the level of activity and this does not depend on the perspective or opinion of people. Moreover, others such as "When whales jump out of the water, are they happy?" or "Are red tulips prettier than tulips of other colors?" are too subjective, and therefore these are not testable.