The Arabian Desert / third-largest in the world / cover / nearly 1 million square mile of the Arabian Peninsula

A. The Arabian Desert, is third-largest in the world, covers nearly 1 million square mile of the Arabian Peninsula. 

B. The Arabian Desert, that is third-largest in the world, covers nearly 1 million square mile of the Arabian Peninsula.

C. The Arabian Desert, third-largest in the world, covers nearly 1 million square mile of the Arabian Peninsula.

D. The Arabian Desert, third-largest in the world, therefore, covers nearly 1 million square mile of the Arabian Peninsula.