Arrange the following events related to European Integration in the correct chronological order.

(A) The Schengen Agreement abolishes border controls among the European Community members.
(B) Unification of Germany
(C) Referendum in Britain to decide Britain's exit from European Union.
(D) First direct elections to the European Parliament

Choose the correct sequence from the options given below:

(D), (A), (B), (C)

The correct answer is Option (2) → (D), (A), (B), (C)

(D) First direct elections to the European Parliament: 1979 June
(A) The Schengen Agreement abolishes border controls among the European Community members.:  1985 June
(B) Unification of Germany:  1990 October
(C) Referendum in Britain to decide Britain's exit from European Union.:  2016