In Return for His Oral Promise to Pay Her $100

In return for his oral promise to pay her $100, Emma promises her uncle that she will not violate laws against speeding for one year. Emma abides by her promise, but her uncle refuses to pay. Which of the following is true regarding whether Emma is entitled to the money?

A) Emma is entitled to the money because she upheld her part of the bargain.
B) Emma is not entitled to recover because she had a preexisting duty to obey laws against speeding.
C) Emma is not entitled to recover because obeying traffic laws was actually good for her, not something that would constitute a detriment.
D) Emma is not entitled to recover unless the agreement was put under seal.
E) Emma is entitled to recover, but only ½ of the amount, because a family member is involved and the agreement was not in writing.