If six coins are flipped simultaneously, the probability of getting at least one heads and at least one tails is closest

[Gmat_mission]

If six coins are flipped simultaneously, the probability of getting at least one heads and at least one tails is closest to

A) 3%
B) 6%
C) 75%
D) 94%
E) 97%

Answer: E

Source: Veritas Prep