Which of the following is most likely to be passed on to the next generation

a.a mutation in the DNA in cells in the testicles
b. blindness from drinking methanol
c. increased muscle mass resulting from exercise
d. a mutation that caused breast cancer
e. a mutation resulting from too many sun burns

a.a mutation in the DNA in cells in the testicles

but only if that mutation was in a cell that divides to produce sperm cells. There are a lot of cells in the testes that are not spermatocytes.