Scientists are worried about the rise of methicillin-resistant Staphylococcus aureus (MRSA)because
A)approximately 1/3 of people harbor this species on their skin and in their nasal passages. B)MRSA can compete with penicillin. C)we now have multi-drug resistant strains of MRSA. D)recently appearing MRSA strains, such as clone USA300, can cause lethal infections of the skin, lungs, and blood. E)C and D