Problem: In guinea pigs, the brown coat color allele (B) is dominant over red (b), and the solid color allele (S) is dominant over spotted (s). The F1 offspring of a cross between true-breeding, solid-colored guinea pigs and red, spotted pigs are crossed. What proportion of their offspring (F2) would be expected to be red and solid colored?
a. 1/9
b. 1/16
c. 3/16
d. 9/16
e. 3/4