Which sentence best summarizes darwin's theory of evolution by means of natural selection?
a. the most fit organism will survive environmental changes and pass on its genes to its offspring.
b. the organism with the most genetic mutations will pass on its genes to the next generation.
c. the least adaptive organism will remain unchanged and pass on its genes to the next generation.
d. the most fit organism will maintain a stable mutational rate and pass on its genes to its offspring.