Answer:
A
Step-by-step explanation:
The correct answer would be that the availability of food resources for black mice and brown mice will decrease.
Since the food requirements of the black mice are the same as that of the invasive brown mice, the available food supply that used to be only for the black mice would now be shared by the two strains of mice. Hence, the available food for the two groups of mice will naturally decrease.
There is no sufficient information to conclude that the population of tan mice will decrease, hence, option B is incorrect.
The black mice and tan mice have different food requirements going by the information available in the illustration, hence, both cannot compete for food resources. Option C is, therefore, incorrect. In the same vein, option D is incorrect because the tan mice have different food requirements from the brown mice.
The only correct option is A.