You recently got strep throat, caused by streptococcal bacteria. You took antibiotics, and your strep throat seemed to be cured. However, a week later, the symptoms of strep throat are back and the antibiotics are no longer effective. The survival of the antibiotic-resistant streptococcal bacteria can be attributed to . Select one: a. Genetic Frequency b. Hardy Weinberg Equilibrium c. Stochastic Events d. Natural Selection