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

Multiple Choice

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. The total angular momentum of the system of the two blocks and the pulley relative to the axis of rotation of the pulley is Use this exhibit to answer the following question(s) .
-Refer to Exhibit 11-1. 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.