The contract law concept of mitigation applies to which of the following circumstances?

(a). A tenant's offer to surrender the premises that is accepted by the landlord.

(b). A tenant's abandonment to which the landlord responds by re-entering and re-letting the premises on behalf of the landlord

(c). A tenant's abandonment to which the landlord responds by re-entering and re-letting the premises on behalf of the tenant.

(d). To b. and c., but not to a