Two Blocks of Masses M1 and M² Are Connected by a Light

Two blocks of masses m1 and m² are connected by a light cord that passes over a pulley of mass M, as shown. Block m² slides on a frictionless horizontal surface. The blocks and pulley are initially at rest. When m1 is released, the blocks accelerate and the pulley rotates.
​ ​
Use this exhibit to answer the following question(s) .
-The total angular momentum of the system of the two blocks and the pulley relative to the axis of rotation of the pulley is

A) the same at all times.
B) proportional to l1, the length of string from the pulley to m1.
C) proportional to l2, the length of string from the pulley to m².
D) conserved because the Earth doesn't move.
E) proportional to the speed of the blocks.