Depolarization of the sarcolemma means A. the inside of the membrane has become less negative as sodium ions accumulate
B. the outside of the membrane has become less negative as sodium ions accumulate
C. the inside of the membrane has become more negative as sodium ions accumulate
D. the sarcolemma has completely lost any electrical charge

Depolarization of the sarcolemma means that the inside of the membrane has become less negative as sodium ions accumulate.

Explanation:

Depolarization consists of a decrease in membrane potential, promoted by the movement of ions that generates a change in this membrane potential at the intracellular level.

At rest, the intracellular space tends to have a negative membrane potential, with respect to the extracellular one. The entrance of sodium ions (Na⁺) through the membrane produces a change, in which the intracellular membrane potential will be less negative.

In the sarcolemma, the entrance of Na⁺ ions produces a decrease of the negativity of the membrane potential, with the exit of intracellular calcium, by the sarcoplasmic reticulum. This is the mechanism responsible for initiating muscle contraction.