Read the excerpt from "Object Lesson, Part 2."

Ellery searched everything in the room, from the socket of the American flag to the insect-filled bowls of the old light fixtures, reached by standing on desks.

Everything.

"It's not here!" whispered Louise in his ear.

What is the source of tension in this excerpt?

A. Ellery searching everything
B. insects filling the light fixtures
C. Ellery standing on the desks
D. Louise Carpenter whispering