Answer:
In ancient times, Nubia was the principal corridor where "there were cultural influences transmitted" between Black Africa and the Mediterranean basin.
Option B is the the right tense of this sentence correction task "b. through which cultural influences were transmitted".
Explanation:
B. The explanation structure is incorrect making the sentence sound very jibberish.
It's not C. There should be a comma where the semi colon is
It would be the answer A.
