Have you ever been at sea in a dense fog, when it seemed as if a tangible white darkness shut you in, and the great ship, tense and anxious, groped her way toward the shore with plummet and sounding-line, and you waited with beating heart for something to happen? I was like that ship before my education began, only I was without compass or sounding-line, and had no way of knowing how near the harbour was. Which statement best describes the purpose of the imagery in the excerpt?

A. It allows the reader to feel how lost Helen feels before she learns to communicate.
B. It allows the reader to feel how excited Helen feels when her new teacher arrives.
C. It keeps the reader in suspense and eager to find out what happens to Helen.
D. It paints a picture for the reader of how dangerous it is to be lost at sea.