Choose the correct form of adverb for the given sentence:
There is heavy fog at the Dhaka airport. The plane, ___________, has been diverted.

- The adverb 'still' means up to and including the present or the time mentioned; even now or then as formerly.
- The adverb 'therefore' means for that reason; consequently.
- The conjunction 'because' means for the reason that; since.
- The conjunction 'although' means in spite of the fact that; even though.
- Hence, the complete sentence is: There is heavy fog at the Dhaka airport. The plane, therefore, has been diverted.​