The answer to your question is b
The pull factors that attracted European Jews to Eastern Europe during the late Middle Ages were that Jews were attracted to Eastern Europe because they could practice Judaism there without any persecution.
So A.
A hypothesis is a a tentative explanation that can be tested and is falsifiable
Explanation:
A hypothesis is in a sense an unverified theory but it can be tricky to define it as such as sometimes some hypothesis are obvious but it is hard or impossible to prove them.
At that point they are taken as givens but it is rather easier to take that the hypothesis is a tentative explanation for something that is largely accepted in the scholarly community but has the scope to be proven to be falsifiable.
