Developmental milestones in a well 4 month old

Sarah, a healthy infant born at 40.5 weeks gestation after an uncomplicated pregnancy, is brought in for a four-month well child visit. Parents report the infant is feeding well, smiling frequently, and becoming more interactive with family members. Which of the following is most consistent with a normal developmental exam for an infant of this age? A. Rolls back to abdomen and transfers objects hand to hand B. brings hands together and laughs out loud C. Lifts head briefly when prone a...