Final answer:
The correct answer is D) recessive, dominant. Loss of function alleles in haplosufficient genes are recessive because one wild-type allele can sustain normal function; gain of function alleles are dominant as they can influence the phenotype even in the presence of a wild-type allele.
Step-by-step explanation:
For haplosufficient genes, loss of function alleles are usually recessive to wild type alleles, while gain of function alleles are often dominant to wild type alleles. The correct answer to the question is D) recessive, dominant.
When a haplosufficient gene has a loss of function mutation, a single wild-type allele is sufficient to maintain normal function, making the mutant allele recessive. However, in the case of gain of function mutations, such as those seen in oncogenes or dominant negative mutations, the mutant allele can interfere with the function of the wild-type allele in a heterozygote, manifesting in a dominant inheritance pattern.
The correct answer is D.