<prompt> a 16-week old child which is expectedMake polysyllabic vowel soundsGet excited at sight of foodEnjoy mirrorAll of the above  <response>: Milestones of development at 16 weeks Social: Laughs out loud; may show displeasure if social contact is broken; excited at sight of food. Prone: Lifts head and chest, head in approximately veical axis; legs extended. Supine: Symmetric posture predominates, hands in midline; reaches and grasps objects and brings them to mouth. Standing: When held erect, pushes with feet. Sitting: No head lag on pull to sitting position; head steady tipped forward; enjoys sitting with full truncal suppo. Adaptive: Sees pellet, but makes no move to it. 