Answer:
D - A proposed explanation for a set of observations.
Explanation:
A hypothesis, as the exercise states, is a proposed explanations for a set of observations. It means to explain a certain phenomenon, why has something worked out in the way it did. So, all in all, a hypothesis is an explanation made out of the limited evidence that means to be the starting point for further investigations or hypothesis. Every hypothesis solves a question and works to formulate another. For example, when solved that such a thing as gravity existed, a question like "why does it exist" arrived.
