$20-$ if the purchaser of a timeshare wished to waive his right to rescind the purchase. Which of the following is true?

A$-$ he may only do so if the timeshare purchase contract includes a provision for cancelation after the first use of the timeshare property

B$-$ he must wait at least $24$ hours after signing the purchase contract before he can waive his right to rescind

C$-$ he may only do so if the timeshare purchase is for a contract period of less than five years.

D$-$ he may not waive his right to rescind under any circumstances