A food chain contains oak trees (producer), mice (herbivore), black rat snakes (carnivore), and bald eagles (carnivore). How many trophic levels does this food chain have? *

It has 4 trophic levels.

Explanation:

The first level would be the producers, followed by the primary consumers, then the secondary consumers, then the tertiary comsumers.

              /    Tertiary consumers          \

           /   Secondary Consumers           \

        /    Primary Consumers                     \

     /           Producers                                   \

 /\