In the Punnett Square Shown Below,the Lettered Circles on the Top

In the Punnett square shown below,the lettered circles on the top and left of the square (indicated by the arrows) represent the

A) offspring that will be produced by the cross.
B) genotypes of the parents involved in the cross.
C) gametes that may be produced by each parent involved in the cross.
D) offspring that could be produced by the cross.