(buyer of 96 acre tract (out of 100 acres) held right of first refusal on remaining four acres; seller sent buyer notice of intent to sell portion of four acre tract, but right of first refusal not exercised and action for declaratory relief filed and trial court granted buyer's motion for summary judgment; appellate court determined that trial court erred in determining that buyer had right to purchase entire four acre tract, and failure to exercise the option caused right of first refusal to expire).