Terrorism is a serious hazard to the country.

The correct answer is B. peril.

A hazard is a source of danger or risk. A peril is a serious and imminent danger or risk. Terrorism is a serious and imminent danger or risk to the country, as it can cause widespread death, destruction, and fear.

The other options are incorrect because they do not accurately describe the nature of terrorism.

• Chance is an opportunity for something to happen. Terrorism is not an opportunity, but a danger.
• Safety is the state of being protected from or not exposed to danger. Terrorism is a danger, not a state of being protected from danger.
• Problem is a situation that is difficult or troublesome. Terrorism is a problem, but it is also a danger.