In June, 1988, John Simpson Granted to His Son, D

In June, 1988, John Simpson granted to his son, D. Bruce Simpson, the right to purchase various parcels of real property that were held initially by John's revocable trust and later by his wife's (Mildred Simpson) revocable trust. The 1988 option agreement provided that Bruce could exercise the option at any time on or before 20 years from the date of the agreement and contained the following clause: "[i]n consideration for the mutual promises made in this agreement."
When some of the properties were transferred to Mildred's trust in 1993, Bruce executed a waiver of the option only to facilitate the transfer of the properties for estate planning purposes, and Mildred executed a written agreement ratifying and incorporating John's 1988 option agreement. John died in 2002, and Mildred died in 2006. The properties were thereafter administered by John's and Mildred's trusts. In April 2008, Bruce exercised the option on several of the parcels. Bruce then died in March 2009. In April 2009, the personal representative of Bruce's estate completed the purchase of the properties.
Chris, who is John's other surviving son, filed a petition challenging the validity of the 1988 option agreement because of a lack of consideration with the vague clause. Family members testified that the mutual promises were related to John staying in the area, caring for his parents, and running the family fruit farm because Chris had left home and did not want to run the business.
-John exercised the option:

A) After it had expired.
B) Within the 20-year time period.
C) Without the authority to do so.
D) Too late because his parents had died.