Answer and Explanation:
We know that shrubs are primary producers and mountain lions are secondary or tertiary consumers. Therefore, mountain lion cannot directly feed on shrub rather need a herbivore. Therefore, to develop a food chain including mountain lion and shrub, we need to have at least one herbivore. If we add a deer between these two, the food chain willl be complete. The deer (herbivore) will eat shrub and mountain lion (carnivore) will eat deer. The food chain can be written as follows
Shrub -> deer -> Mountain Lion
