Tony is a 12th-grade boy who is having trouble learning about anatomy. Seeing this, Tony's teacher has asked Gladys, a bright classmate of Tony's, to help him understand the concepts he's having trouble with. Deciding to have Gladys help Tony learn anatomy, the teacher is helping Tony work within his
a. fluid intelligence.
b. absolute performance.
c. zone of proximal development.
d. triarchic theory of intelligence.