The botanist's discovery transformed our understanding of ancient plant biology ______ fossilized leaves contained intact chemical signatures of photosynthesis from 200 million years ago.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A
;
- Bcheck_circle
:
- C
(empty)
- D
, which
Explanation
A colon introduces an explanation of how the discovery transformed understanding. A semicolon could work but a colon better signals explanation; " " is a run-on; ", which" creates an unclear modifier.