Which is the best source of historical evidence to learn about how an event unfolded?

How did the catholic church change as a result of the council of trent? a. catholic printers were encouraged to publish translations of the bible in common languages b. members of the catholic clergy were required to avoid luxurious lifestyles c. catholics were told they could earn salvation through god’s grace alone d. european catholics were barred from initiating any conflict with protestants.

Which piece of information would most a historian create an interpretation of this photograph of works in a factory?

Poland a: nato b: warsaw pact c: not a member of either alliance