If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, and has both number 19 chromosomes with short genes, she will produce which of the following egg types?

a. only blue short gene eggs
b. only orange short gene eggs
c. only orange short gene eges one half blue short and one half orange short gene eggs
d. three fourths blue short and one fourth orange short gene eggs