Given the parents aabbcc × aabbcc, assume simple dominance for each trait and independent assortment. what proportion of the progeny will be expected to phenotypically resemble the first parent?
a) 1/4
b) 1/8
c) 3/4
d) 3/8
e) 1

The answer is C) 3/4

Let's analyze separately each of the traits:

Parental generation: AA x Aa
F1 generation:       AA AA Aa Aa
So, all progeny will phenotypically resemble the first parent.

Parental generation: BB x bb
F1 generation:       Bb Bb Bb Bb
So, all progeny will phenotypically resemble the first parent.

Parental generation: Cc x Cc
F1 generation:       CC Cc Cc cc
Only 3 (CC, Cc, Cc) out of 4 progeny will phenotypically resemble the first parent.

The genotypes for first two traits will not affect phenotypical resemblance to the first parent. So, it only counts the third trait, for which the chance to have progeny that phenotypically resemble the first parent is 3/4.