Shams, Kamitami, and Shimojo (2001) Briefly Flashed a Spot of Light

Shams, Kamitami, and Shimojo (2001) briefly flashed a spot of light, sometimes only once and other times twice or more in rapid succession either unaccompanied by sound or accompanied by brief, auditory clicks. They found that,

A) when there was no sound, people accurately reported the number of flashes.
B) when there was sound, people accurately reported the number of flashes.
C) when people heard two clicks, a single visual flash was perceived as two successive flashes.
D) all of these