Ascientist studying where eastern king snakes lay their eggs observes that females lay eggs under pieces of old tin in the sunshine during cold years and under thick rocks in shady areas during warm years. based on what he knows about snake egg laying physiology, he says to his research assistant; i think the female snakes perceive average temperatures and change their behavior depending on how warm the weather is that year. the scientist stated a/an to his assistant.

The answer is - hypothesis.

In here we have a situation where the scientist has be observing a certain behavior of the snakes under certain conditions. So he has some basis for proposing it as new exciting discovery, but the evidence are still basic ones and further investigation is needed.

Considering the definition for what is a hypothesis - ''a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation'' - it perfectly fits the given scenario.