The Sahara Desert ______ covering an area larger than the contiguous United States ______ continues to expand southward at a measurable rate.
Which choice completes the text so that it conforms to the conventions of Standard English?
- A
/
- B
/ ,
- C
, /
- Dcheck_circle
, / ,
Explanation
The participial phrase "covering...United States" is nonrestrictive (the Sahara is uniquely identified) and must be set off by paired commas.