The author uses paragraphs eight, nine, and ten

Responses
A to explain how the Dream Machine brought Derek back from ancient Greece.to explain how the Dream Machine brought Derek back from ancient Greece.
B to illustrate how to program the Dream Machine to take someone into the past.to illustrate how to program the Dream Machine to take someone into the past.
C to show that Derek succeeded in using the Dream Machine to complete his project.to show that Derek succeeded in using the Dream Machine to complete his project.
D to demonstrate that Derek’s presentation was better than those of his classmates.

C to show that Derek succeeded in using the Dream Machine to complete his project.