When Mr. Baker was declared mentally incompetent, the court appointed Mary, his daughter, to act on his behalf. Several years later, Mary asked her sister, Betty, to manage their father's affairs. If Betty enters into a listing contract for the sale of their father's home, will the listing contract be valid

This choice is incorrect because Mary does not have the legal authority to appoint Betty to act on their father's behalf. Only the court could formally designate someone to manage Mr. Baker's affairs, and without such appointment, Betty's actions would not be legally valid.

This option is also incorrect. Mr. Baker, being declared mentally incompetent, cannot provide valid consent to any contracts or agreements. Therefore, even with his written consent, Betty would still lack the legal authority to act on his behalf.

While it is true that contracts involving the property of a mentally incompetent person can be void, this choice does not fully capture the reason for the invalidity in this case. The primary issue here is that Betty has not been legally appointed to act on their father’s behalf, rather than the inherent void status of contracts involving mentally incompetent individuals.