Ms. Smith properly executed a power-of-attorney authorizing Mr. Jones to sign a deed for her, pursuant to the closing of a sales contract. Unknown to Mr. Jones or to the purchaser at the time, Ms. Smith died the night before Mr. Jones signed the deed. Under these circumstances:
A. the conveyance is probably valid.
B. the conveyance is not valid.
C. a power-of-attorney lasts until revoked by will of the grantor.
D. power-of-attorney is effective for 60 days after the lifetime of the person granting such authority.