_______ they are twins, they are worlds apart in their attitude to life.

Options

A. Although
B. Despite
C. Whereas
D. However

Explanation

(a) “Although” should be used. Although is used to introduce a subordinate clause that contains a statement that contrasts with the statement in the main clause. In this sentence, the main clause is “they are worlds apart”, so the subordinate clause “they are twins” should be used with “although”