Sonja Put on a New Watch This Morning and Found

Sonja put on a new watch this morning and found it uncomfortable because it was so much heavier than her old watch. However, at noon, when a friend asks her if she knows what time it is, Sonja finds she has forgotten she is even wearing the watch. The change in Sonja's sensitivity to the pressure of the watch illustrates the process known as

A) sensory adaptation.
B) perceptual invariance.
C) perceptual assimilation.
D) adjusting just noticeable differences.