Final answer:
As a legal requirement, an exclusive listing between a broker and seller must have a definite termination date to ensure clarity of the agreement's duration and prevent indefinite obligations.
Step-by-step explanation:
In an exclusive listing, as a matter of law, a listing between the broker and seller must have a definite termination date. This requirement ensures that the agreement between the two parties is clear and time-bound, preventing any indefinite obligations. It is common for the duration of such listings to be set for a few months, but there is no standard period mandated by law; it is negotiated and agreed upon by the broker and the seller at the time of contract creation. Therefore, the options suggesting a pre-determined period of three months or 90 days are not correct without context, and the option stating there is no specified term goes against the legal requirement for a definite term in such agreements.