The correct answer is (B) Make ineffective; To render neutral, render ineffective, counteract, or counterbalance by opposite force or effect. In international law, to make a country neutral. In chemistry, to modify specific properties of a substance; in physics, to make electrically inert.

Neutralize comes from French neutralizer, Latin neutralisare.

Examples of use:

• Your carelessness has just neutralized all our efforts.
• The ruler dispatched troops to the village to neutralize any opposition.