A party planner contracted to rent a rooftop patio from a vendor for a festival party. The party planner rented the patio based on the belief that the planners clients would be able to see the citys fireworks display from the patio. In order to ensure that the patio would be safe, the vendor visited the building upon which the patio was to be placed, took measurements, and inspected the condition of the roof. However, a week before the party, the building was destroyed in a fire.

Which of the following arguments can the party planner successfully use to refuse to pay for the patio?

a) It is impossible to use the patio to see the fireworks.

b) The purpose of renting the patio has been frustrated by the destruction of the building