Drug-resistant tuberculosis is a major health issue in many countries. Treatment for these resistant forms of bacteria is longer and requires more expensive antibiotics. Scientists attribute this to natural selection. Under these circumstances, what does natural selection mean? A. The tuberculosis genes mutated to avoid being killed by the antiblotic
B. Tuberculosis bacteria discovered a way to avoid these particular antibilotics.
C. An environment was created in which the tuberculosis bacterium carrying the antibiotic-resistant genes could reproduce.
D. The antibiotic changed the DNA of the tuberculosis bacterium.