Because of the confounding factors, additional criteria have been developed by the U.S. public health service for pit-and-tissue caries diagnosis. Which one of the following is NOT a factor of these criteria?
A
Softening at the base of the pit or fissure
B
Opacity surrounding the pit or fissure
C
Softening enamel that may be flaked away by the explorer
D
Discoloration of pit and groves, limited to the depth of the fissure or pit.