Answer:
The answer is: A) infant sucking
Contemporary psychologists are most likely to consider infant sucking to be a human instinct.
Explanation:
Human instinct is something innate to the living being, a type of intelligence in its most primitive degree. He guides man and animals in their trajectory through life, in their actions, aiming precisely at the preservation of being. Because of that, the infant sucking is a human instinct, once it's something innate and used to preserve the species. The baby just knows how to suck the mother's milk, but there's no explanation for that. It's innate.
