Selection — practice question

These events can occur when an antibiotic is used to treat a bacterial infection. Which sequence could result in a strain of antibiotic resistant bacteria?

• A1 → 2 → 3 → 4
• B2 → 3 → 1 → 4
• C3 → 1 → 4 → 2
• D4 → 1 → 3 → 2