Explanation:

- Void: A contract that has no legal force from the beginning. This isn't the case here since a valid rental agreement existed initially.

- Discharged: A contract is considered discharged when obligations under it are completed, or resolved. Correct Answer: This applies here as the tenancy ends because A now owns the house.

- Rescinded: This refers to a contract being canceled by mutual agreement, restoring parties to original positions. This doesn’t apply since A purchasing the house is not about canceling the agreement but fulfilling and moving beyond it.

- Voidable: A contract that is initially valid but can be voided by one party. This isn't applicable because the purchase doesn't render the initial contract voidable.