Monkeys eating bananas because it's their favorite food
This is not a difficult question because this is the easiest question of the world because every person knows that monkeys are crazy for bananas.
In this video you can see how the monkeys eating bananas hobby and people feed bananas to make them happy. They feels strong after eating banana that's why they were not scared of the dog. Banana and monkey has a strong positive relation with each other.
In simple words we can say that, banana is the favorite food of monkeys.