Answer:
D). Anxiety disorders are caused by a combination of genetic and environmental influences.
Step-by-step explanation:
Hypothesis is described as the tentative supposition that aims to explain an observation, phenomenon, or problem which could be further challenged or tested. It is also described as the assumption for the sake of argument.
In the given question, option D displays the proposition that would not be categorized as a hypothesis as it doesn't state a proposition to a problem but instead states its factual cause. Thus, option D is the answer.