Arrange the following former UN Secretary Generals in order of their having hold the office.
A. Dag Hammarskjöld
B. U Thant
C. Boutros Boutros-Ghali
D. Javier Perez de Cuellar
Choose the correct answer from the options given below:
1
B, C, A, D
2
C, B, D, A
3
A, B, D, C
4
D, A, C, B