The correct option is A in case of a tie, viz.when the votes an equally divided
A casting vote is a vote which may be exercised (usually in addition to his or her normal vote as a member of the body, if he or she has one) by the presiding officer of a council or legislative body, or of any committee, to resolve a deadlock and which can be exercised only when such a deadlock exists. The Speaker of the Lok Sabha makes use of his casting case in the above situation.