Natural selection has fueled the rise in MRSA
(methicillin-resistant Staphylococcus aureus) infection by:
| a, enabling people to use a greater variety of antibiotic drugs to fight the infection. |
| b. inactivating a greater variety of antibiotic drugs. |
| c. | enabling certain bacterial variants to survive in the presence of many antibiotic drugs. |
| d. | killing all bacteria exposed to antibiotics, including helpful ones. |





