Answer:
Nothing will happen.
Step-by-step explanation:
Nothing will happen to the octopus population if the number of snails decreased or extinct in the area because there are many other organisms on which octopus can feed. Octopuses feed on crabs, small fishes, clams, snails, and on other octopuses so if other food sources are available to Octopus so there is no effect on the Octopus population but if there is no other food source then the Octopus population will definitely decreases due to lack of food.