Termination by Agreement or$/$ Frustration

Question $4$ options:

Johnny rents equipment from Doe at a rate of $$500$ per month. The term of the contract is $2$ years. Six months into the term, the equipment is destroyed in a lightning strike, and Johnny has to rent new equipment from another supplier.

Keith enters into a written contract to purchase drilling equipment from Justin. Subsequently, Justin requests that the price and terms of delivery be changed, and Keith agrees to Justin's request.

An unexpected change in the law, makes performance of the contract illegal.

A party to the contract dies where the contract requires the party to perform a personal service.