Marcy is trying to define "anxiety" in such a way that it specifies how it is to be observed, measured, and empirically tested. She is attempting to find an appropriate:

Studies by Shiner, Thomas, and Chess indicate that newborn infants differ in activity, irritability, and other aspects of

a. intelligence. b. physical development. c. temperament. d. aggressiveness.

Pediatric psychologists received specialized training in

a. the administration of children's hospitals. b. mental health problems associated with physical conditions. c. the administration and prescribing of medications to children. d. all of the above