Final answer:
The snake would most directly cause the mouse population to decrease in the food web.
Step-by-step explanation:
The snake would most directly cause the mouse population to decrease.
In a food web, an organism that consumes another organism is called a predator. The snake is a predator of the mouse, so if the snake population increases or the mouse population decreases, the snake will have more food and the mouse population will decrease.
For example, if there are fewer snakes due to a decrease in their prey (such as frogs and crickets), the snake population will decrease and the mouse population may increase. On the other hand, if there are more snakes, the snake population may increase and the mouse population will decrease.