The Voyager 1 spacecraft ______ continues to transmit data from interstellar space more than four decades after its initial launch.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A
— launched in 1977
- B
launched in 1977
- Ccheck_circle
(launched in 1977)
- D
launched in 1977
Explanation
A parenthetical aside providing supplementary detail about Voyager 1 is properly enclosed in parentheses. Without any punctuation, the phrase would create a run-on.