Sara,age 4 Months,was Born at 35 Weeks' Gestation

Sara,age 4 months,was born at 35 weeks' gestation.She seems to be developing normally,but her parents are concerned because she is a "more difficult" baby than their other child,who was term.How should the nurse explain this difference to the parents?

A) Infants' temperaments are part of their unique characteristics.
B) Infants become less difficult if they are not kept on scheduled feedings and structured routines.
C) Sara's behaviour is suggestive of failure to bond completely with her parents.
D) Sara's difficult temperament is the result of painful experiences in the neonatal period.