In the Contract Between Gamil's Building Materials Store and Hightrees

Multiple Choice

In the contract between Gamil's Building Materials store and Hightrees Logging and Lumber Company for the supply of lumber, there is a clause that allows either party to end the contract on 10 days' notice should actions of logging protesters on Hightrees property bring logging operations to a temporary halt. This clause is a(n) :

A) Frustration of contract clause
B) Condition subsequent clause
C) Force majeure clause
D) Option to terminate