Which of the following is an example of social referencing? a. katie (a 13-month-old girl) cries and reaches for her father when she falls down and scrapes her knee. b. andrew (a 4-month-old boy) cries when his mother puts him down after she has been holding him. c. olivia (a 15-month-old girl) looks at her mother before she smiles at an unfamiliar woman. d. mark (an 8-month-old boy) plays patty-cake with his father and laughs and smiles when his father tickles him.