White fruit color in summer squash is governed by a dominant gene (W) and colored fruit by its recessive allele (w). Yellow fruit is governed by an independently assorting hypostatic gene (Y) and green by its recessive allele (y). When dihybrid plants are crossed, the offspring appear in the ratio of 12 white : 3 yellow : 1 green. What fruit color ratio is expected from the cross of WwYy to Wwyy?
a) all white
b) 1/2 white, 1/2 yellow
c) 1/2 white, 1/4 yellow, 1/4 green
d) 1/2 white, 1/2 green
e) 1/4 white, 1/2 yellow, 1/4 green