A cross between a wild-type fruit fly strain and various true-breeding mutant strains (all at a single locus) for bristle mutations resulted in the...

A cross between a wild-type fruit fly strain and various true-breeding mutant strains (all at a single locus) for bristle mutations resulted in the following phenotypes:

Mutant Bristle Phenotype (THIS IS NOT THE QUESTION)

1 0.20 shorter

2 0.30 longer

3 0.50 shorter

4 bent and damaged

5 no bristles

Using Muller's Morphs classification, which of these mutants would be classified as a "hypomorph"? (THIS IS THE QUESTION)

A. Mutant 3

B. Mutant 2

C. Mutant 5

D. Mutant 1

E. Mutant 4