Answer:
The correct answer is -
A) Fungal contraction to the oak tree
B) Less precipitation.
Explanation:
A biotic factor is the living thing present in an ecosystem and affects the system and leads to changes in the system. Here fungus is a living organism that influences the population size of the oak tree and the squirrels negatively.
An abiotic factor is a non-living thing condition or factor that affects the system and leads to the changes. In this case, the high temperature and the low rate of precipitation lead to changes in the size of the population.