The teacher of a sixth-grade class is concerned about the poor academic performance of a 12-year-old student named nancy. the teacher looks through nancy's school records and discovers that nancy got an iq score of 80 when she took an intelligence test in preschool. considering the textbook's discussion of iq scores, the teacher should conclude that: a. nancy's iq is mostly an inherited characteristic, so there is little the teacher can do to improve her learning potential. b. nancy's iq is largely the result of environmental conditions; given proper stimulation, instruction, and curricular materials, it can probably be raised as much as 30 points over the next school year. c. nancy's iq score in preschool is not necessarily a good reflection of her capability in sixth grade. d. nancy may still be at piaget's preoperational stage of cognitive development.