Your Answer is

Correct Answer is H

Explanation

The two triangles are similar, so DC : DB = 1200 : 2000 = 3 : 5,

DC : (DB-DC) = 3 : (5-2)

DC : BC = 3 : 2

Therefore, the ratio of BC to DC is 2/3, and the length of DC is 3960. Choose H.