Answer:
Reduced penetrance or incomplete penetrance
Explanation:
Penetrance refers to the extend which a certain gene or set of genes is expressed in a population.
It can be complete where there is expression of the gene in a population having it.
Whereas, in reduced penetrance is where the mutation is not expressed in every individual in the population having it.
For instance polydactyly exhibits reduced penetrance since the parents had the mutation it was not expressed it came to be expressed on their pedigree.
B... cause that’s the only one for that.
