Question: PLEASE EXPLAIN not just answer, Thanks Four individuals were found to be homozygous for a recessi…

PLEASE EXPLAIN not just answer, Thanks

Four individuals were found to be homozygous for a recessive
mutation known to cause heart disease. However, only three of the
four individuals actually have heart disease. What is this an
example of?

A) Variable expressivity B) Pleiotropy C) Epistasis D)
Incomplete Penetrance E) Synthetic lethality