Step 1: Understanding the Question:
The question presents a scenario where A leases a house to B on the condition that the lease continues as long as B resides in it.
We need to categorize the type of condition attached to this transfer.
Step 2: Detailed Explanation:
• Condition Precedent: A condition that must be fulfilled before an estate can vest in the transferee.
Here, the lease is already vested in B, so it is not a condition precedent.
• Condition Subsequent: A condition that divests or terminates an already vested estate upon the occurrence or non-occurrence of an uncertain future event.
• Collateral Condition: A condition that runs alongside the estate, determining its duration without divesting it abruptly upon an external contingency.
In this case, the condition of "residing in the house" is an ongoing state of affairs that defines the very span of the lease.
It is collateral because the existence of the interest is co-extensive with the performance of the condition.
The lease automatically expires when B ceases to reside in the house, acting as a limitation or collateral limitation rather than a simple divesting condition subsequent.
Step 3: Final Answer:
The transfer is subject to a collateral condition, making Option D the correct answer.