A Teacher Has Been Told That His Students Are Exceptional

A teacher has been told that his students are exceptional.In order for the Pygmalion effect to occur,what has to happen next?

A) The teacher goes out of his way to avoid treating these students differently,and researchers find no differences in students' treatment a year later.
B) The labelling of the students has no significant impact on their IQ scores.
C) There are marked academic gains among the so-called "extremely intelligent" students.
D) The teacher's positive expectations actually create less successful students.