Underexposed Projections That Require Repeating Are Identified by All of the Following

Underexposed projections that require repeating are identified by all of the following except
1) quantum noise is present.
2) the VOI demonstrates a loss of contrast resolution.
3) the EI number indicates less than optimal exposure and no histogram error has occurred.
4) the overall image is gray.

A) 1, 2, and 4 only
B) 2 and 3 only
C) 1, 2, and 3 only
D) 1 and 4 only