The correct answer is D. Contact comfort
Explanation:
Harry Harlow was an important American psychologist that lived during the 20th and mainly know for carrying out multiple experiments with monkeys to study social isolation and caregiving this included baby monkeys and their mothers and surrogate mothers created with objects by Harlow. Although these experiments were quite controversial they provided valuable information about attachment between mother and infant including that mother deprivation led to consequences on behavior and socialization and that the most important in the relationship between mother and baby was the physical contact or contact comfort as the lack of it led to distress and harmed the psychological development. Therefore, Harlow found the most important thing to give a newborn for psychological health and well-being is contact comfort.
