The correct answer is (B) To pester, torment; or worry; to bother or disturb repeatedly with questions, demands, troubles, or other unpleasantness. To subject (someone) to continuous attacks or incursions, etc., as in war or hostilities.

Harass comes from French harasser, based on Old French harer (to set a dog on).

Examples of use:

• They harassed her for weeks by telephone and mail.
• After receiving a third telephone call from the bill collector, the delinquent debtor accused the caller of harassing him.