During the late nineteenth century ______ photography began to transform from a cumbersome studio process to a portable everyday medium.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A
(empty)
- Bcheck_circle
,
- C
;
- D
:
Explanation
"During the late nineteenth century" is an introductory prepositional phrase. A comma should follow it before the main clause.