In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (CRCW) offspring of red (CRCR) and white (CWCW) homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red: 2 roan: 1 white?
a) red x white.
b) roan x roan.
c) white x roan.
d) red x roan.
e) all of the above crosses would give the same percentage of roan.