Alan's Saddles Makes High Level Seats for Racing Bicycles and Sells

Alan's Saddles makes high level seats for racing bicycles and sells to many of the top bicycle manufacturers. There are eight available sources of the type of rubber that Alan's uses; however, Alan's has always dealt with a company in the Republic of Anaerobia exclusively due to their reasonable cost. Porter's company has a contract with Alan's for 10,000 seats. Porter has just received a letter from Alan's explaining that due to turmoil in Anaerobia, their supplier cannot export their product so Alan's cannot complete the contract. Which of the following is true of this situation?

A) Alan's can get out of the contract based on impossibility of performance.
B) Alan's can get out of the contract based on commercial impracticality since they can't be forced to buy from suppliers they have not dealt with before.
C) Porter can sue for breach since the raw materials are reasonably available from another source, and Alan's cannot be discharged due to impracticality.
D) Porter can sue for specific performance if the seats are typical of all bicycle seats and not special or unique in any way.
E) Porter can rightfully file a lawsuit, and Alan's will be liable to pay Porter damages for nonperformance.