The correct option is D 25 cm
The rhombus is a parallelogram with equal sides.
Perimeter of the rhombus = 100cm
Let, length of one side of the rhombus is a.
Then, a + a+ a+ a = 100 cm
⇒ 4a = 100
⇒ a = 1004 = 25
⇒ a = 25cm
Length of sides of the rhombus is 25 cm.