Etna is an active volcano. The volcano is on...

Câu hỏi: Etna is an active volcano. The volcano is on the island of Sicily.

A. Etna, which is on the island of Sicily, is an active volcano.

B. Etna which is on the island of Sicily, is an active volcano.

C. Etna, which is on the island of Sicily is an active volcano.

D. Etna, which is on the island of Sicily, is active volcano.