$33.$ Linda is a nurse who became very friendly with Glenn, a sick and elderly patient. Glenn owned real estate worth millions, which he had planned to leave to his children. Linda persuaded Glenn to sell her the property instead for $ $10,000$ by often telling him $"$if your children cared for you at all they would visit more often." Which of the following theories would most likely let Glenn to rescind the contract?

a$.$ duress.

b$.$ undue influence.

c$.$ fraud.

d$.$ misrepresentation.