Answer:
A. increase in American pika population size
Explanation:
Carrying capacity is the idea that relates to how much population can an environment sustain before collapsing. Here, the answer would be A. increase in American pika population size because if you increase the food for weasals, naturally the population carrying capacity goes up because now the environment has food to feed the weasals which can contribute to increasing the carrying capacity (i.e. the environment can now handle larger population of weasel than initial condition)
