Birds such as blue-gray gnatcatchers nest in the canopy of oak trees. They receive shelter from oak trees, while the trees goes unharmed. Thus, these populations have a commensal relationship.
How would the sudden decrease in the size of the blue-gray gnatcatcher population affect the size of the oak tree population?
A. The oak tree population would increase.
B. The oak tree population would decrease.
C. The oak tree population would go extinct.
D. The oak tree population would stay the same.