Haploids are able to express both recessive and dominant alleles /mutations because there are :

Options

A. many alleles for each gene
B. two alleles for each gene
C. only one allele for each gene in the individual
D. only one allele in a gene

Answer

C

Explanation

In haploids there is only one allele for each gene in the individual, that's why haploids are better for mutation work because in them all mutations whether dominant or recessive are expressed.