Blue Flower Color (B Allele)is Dominant to White (B Allele)

Blue flower color (B allele) is dominant to white (b allele) .If a population of plants contains white flowers (bb) at a frequency of 0.04,what is the frequency of the blue flower allele (B) ?
4-9-2013

A) 0.2 or 20%
B) 0.64 or 64%
C) 0.32 or 32%
D) 0.8 or 80%
E) 0.96 or 96%