Purple Flower ( a ) Is Dominant Over White Flower

Purple flower ( A ) is dominant over white flower ( a ) , and tall stem ( B ) is dominant over short stem ( b ) . The Punnett square represents a cross between two dihybrids ( AaBb ´ AaBb ) . Examine the figure above, and answer the following question(s) . In the figure above, what is the ratio of phenotypes in this case?

A) 1: 1:1:1
B) 3:1
C) 6:3:3:1
D) 9:3:3:1
E) 15:1