The correct answer is C. Terorism. The correct spelling is terrorism.
Terrace: a raised area of ground next to or at the side of a building, with steps leading up to it.
Transmitter: a device for sending out radio or television signals.
Tremor: a shaking or trembling movement.
Terrorism: the unlawful use of violence and intimidation, especially against civilians, in the pursuit of political aims.
