The depth of the water on the shore of a beach varies as the tide moves in and out. The equation
D(t) = 0.75 cos (t) + 1.5 models the depth of the water, D(t), in feet and t as time in hours.
1. When will the tide be at its lowest for the first time when t > 0?
A) 3
B) 6
C) 9
D) 12