In Corn R Is a Gene for Red Aleurone;its Recessive

Multiple Choice

In corn R is a gene for red aleurone;its recessive allele r determines colorless aleurone.A cross is made between a diploid r/r female and a trisomic R/r/r male.If pollen grains with extra chromosomes are inviable,the ratio of red to colorless kernels expected in the progeny would be:

A) 1 red : 5 colorless.
B) 1 red : 2 colorless.
C) 1 red : 1 colorless.
D) 2 red : 1 colorless.
E) 5 red : 1 colorless.