Dan dentist was selling the building in which his office was located so that he could relocate to a larger space. ron, a very aggressive commercial real estate broker, told dan that unless he gave ron an exclusive one year contract to list the property, he would spread word in the community that dan was selling his building to pay a large malpractice claim and that dan had been liable in so many malpractice suits that no company would insure him. dan believed that ron would carry out this threat and signed the contract. dan can rescind the contract based on

Duress

Explanation:

Duress is a protection against an agreement. Duress is the wrong pressure to force an individual  into an agreement that he or she would not normally enter into.

Duress involves using force intentionally or  threatening force to induce the agreement.

It may be either physical or mental manipulation, but it must be intimidation to the degree that it robs  the other individual of independent will or freedom of choice.  

This implies that no fair alternative to entering the contract is left to the individual.

the third answer is correct.

answer(b); ; ; the quantitative or qualitative variable for which the experimenter wishes to determine how its value is affected by the explanatory variable;