Read the paragraph from The Hot Zone.

Just then, he noticed a blur of motion on his left, and he turned and saw two Hazleton workers walking toward him. They weren't supposed to be in here! The area was supposed to be sealed off, but they had come in by another route that led through a storeroom. They wore respirators, but nothing covered their eyes. When they saw the two men in space suits, they froze, speechless. Jerry could not see their mouths, but he could see their eyes, wide with astonishment. It was as if they had suddenly discovered that they were standing on the moon.

What is the author’s main purpose for including this paragraph?

to inform readers about the location of the scene that is unfolding
to explain to readers that being a scientist can be exciting work
to entertain readers by illustrating how dramatic the situation is
to reassure readers that the situation was completely under control