The correct answer is (D) To nullify; cancel; overrule. To disregard, to assert one's will, authority, etc. in disregard of. Also, to prevail over; to trample or crush by riding over; to dominate.

Override comes from Middle English overridden, Old English oferridan (to ride across).

Examples of use:

• He overrode the decisions of his predecessor.
• He dispatched a handful of tanks to override the enemy position.