The answer, I believe, would be C) A decrease in the wolf population - because the prey decreases, fewer wolves will be able to find food, which will lead to a decrease in their population.
Weather is short period climate is over a period of years
Clues such as fossils such as bones, footprints, tar, etc, preserved underground helped inform scientists. You can also count how old a tree is when you cut it open and there are some alive for thousands of years so that is a possible way.
