Final answer:
The lowest form of estate in property law is a tenancy at sufferance, which occurs when a tenant remains on the property without the landlord's consent post-lease expiration.
Step-by-step explanation:
The question pertains to the concept of different estates in property law. These are various forms of legal interests or rights in land. The lowest form of estate referred to in the question is a tenancy at sufferance. This particular estate arises when a tenant remains in possession of property after the expiration of a lease, without the landlord's consent but also without being explicitly evicted. Therefore, the correct answer to the student's question is: a) Tenancy at sufferance. Contrasting with this, a tenancy at will allows the tenant or the landlord to terminate the lease at any time. A life estate grants occupancy rights for the duration of a person's lifetime, and concurrent ownership refers to property that is owned by two or more parties at the same time.