The astronomer adjusted the telescope's mirror ______ and recalibrated the tracking software before resuming observations.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A
;
- B
—
- Ccheck_circle
(empty)
- D
,
Explanation
"Adjusted...and recalibrated" is a compound predicate sharing one subject. No comma precedes "and" between two verbs of a single subject.