Describe the effect of the vaccinations on death rate in the wildebeest population

Wildebeest were nearly wiped out by rinderpest virus from cattle. Rinderpest had high mortality in wildebeest especially in young animals, it also caught high mortality rate on cattle and so inoculation attempts started in the 1940's. In 1960's there was largely successful push to vaccinate 80 million cattle across 22 African countries. wildebeests themselves were not vaccinated but as the number of rinderpest infected cattle decreased with vaccination so did the number of wildebeest that had rinderpest disease was essentially eliminated resulting in overshoot of population of wildebeest.

What are the answers

The answer is b, as with an inference you make a statement with no evidence