Russell, an auto insurance agent, knew that Gyle's seventeen$-$year$-$old son, Phelix, was allowed to drive the

covered automobile, and also knew the company did not accept such risks. If Russell issues the policy, the

company looses the right to refuse coverage on this basis later in the policy period. This is an example of:

an estoppel.

a conditional binder.

a contract of adhesion.

a waiver.

a supplementary binder.