Final answer:
The fiancÈ should be asked to sign the surgery consent form because they are the closest representative of the patient's interests.
Step-by-step explanation:
The person who should be asked to sign the surgery consent form is the patient's fiancÈ. In this scenario, the patient is legally divorced, and the physician has explained the need for surgery and the risks to not only the children, parents, and fiancÈ but also the patient's other family members. Since the patient is planning to be remarried in a few weeks, the fiancÈ is considered the closest representative of the patient's interests and therefore should be asked to sign the consent form.