Melanie was assisting in the care of her dying grandmother. The two had numerous conversations in which Melanie threatened to leave her grandmother's bedside unless her grandmother changed her will and left everything to Melanie. Fearing that Melanie would leave, her grandmother relented and changed the terms of her will in Melanie's favor. This is an example of

A$)$ duress

B$)$ fraud

C$)$ an "arm's length" transaction

D$)$ frustration of purpose

E$)$ undue influence