The correct option is C Founder effect
Genetic drift is a change in allele frequency in a population, due to a random selection of certain genes.
Sometimes the change in allele frequency is so different in the new sample of population that they become a different species. The original drifted population becomes founders and the effect is called founder effect.
According to deVries, a single large mutation caused speciation and this phenomenon was called saltation.
Natural selection is the process whereby organisms better adapt to their environment to survive and produce more offspring.