Each of the following is a monocular cue to depth except ___

We tend to see members of a category as embodying the most typical attributes of that category, or what are called ________.

Fill in the blank(s) with the appropriate word(s).

An assembly-line worker nods off during a night shift; co-workers awaken him after no more than 5 minutes. What stage of sleep was this individual in?

a) Stage 1 b) Stage 0 c) Stage 3 d) Stage 4