Which type of contract ensures a property will not be sold to another buyer until its expiration?

The option to buy contract is designed to give a potential buyer the exclusive right to purchase a property within a specified time frame. This type of contract prevents the property owner from selling the property to anyone else during the duration of the option period. The buyer typically pays an option fee for this privilege, which may be applied to the purchase price if the buyer decides to go through with the sale.

In contrast, a lease agreement generally pertains to the rental of property rather than a sale and does not establish a commitment to purchase. A purchase agreement is a binding contract to buy a property, but it usually assumes the buyer has already secured the right to purchase and not someone who might simply be contemplating a potential future purchase. A contingent contract incorporates specific conditions that must be met for the sale to proceed, which does not inherently provide the exclusivity regarding the sale that an option to buy contract offers. Thus, the option to buy contract is the only choice that directly ensures the seller is restricted from entertaining other offers until the option expires.