Antibiotics were once considered a complete solution to bacterial infections ______ widespread overuse has now created drug-resistant strains that pose serious public-health threats.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A
; but,
- B
, but,
- Ccheck_circle
, but
- D
but
Explanation
Comma plus FANBOYS "but" joins two contrasting independent clauses. " but" is a run-on; the others are over-punctuated.