Which one of the following best illustrates expository instruction?
a) Students in Mr. Phillips's English class discuss the themes addressed in Hamlet.
b) Students in Mr. Richards's science class look at handouts and computer-screen projections that depict the life cycle of the butterfly.
c) Students in Ms. Thaller's geometry class work at their desks trying to prove the side-angle-side theorem for triangles.
d) Students in Ms. Verden's history class write the answers to a series of short questions and then share their responses with their classmates.