Answer
Humerus I believe
Explanation
Superior means higher. The only one that is located higher is humerus
Babies typically do not show social smiles
until four to six weeks of age.
Any smiling before that time, it may not be deliberate. It's usually only a sign that the baby is
comfortable, either they just urinated or they just ate.
At
first, the baby smiles at every one but after
several months, most babies save their smiles for people they know.
