When is a mutated gene most likely to be passed along to offspring over several generations?

a.
when the mutations are substitutions

b.
when there are multiple mutations in a gene

c.
when the mutation is beneficial

d.
when the mutation is harmful

"When there are multiple mutations in a gene" is the one among the following choices given in the question that is a mutated gene most likely to be passed along to offspring over several generations. The correct option among all the options that are given in the question is the second option or option "B".