Johnson Ltd

Johnson Ltd.enters into a contract to supply glass bottles to Brine Co.for its line of baby dill pickles.Since it is a new relationship,both parties want the option to end the contract without problems,so they include a clause that allows either company to terminate the contract on 30 days' written notice.Johnson finds that Brine Co.is too slow in paying its bills and too quick to question quality.On March 1,Johnson Ltd.gives Brine Co.notice in writing that the contract will end on March 31.Brine Co.insists that the 30 days' notice clause means 30 working days,not 30 calendar days,and thus Johnson must supply Brine Co.until April 1.Johnson refuses.Brine Co.loses two weeks of production when its supply of bottles runs out and sues Johnson for breach of contract.
-Based on the above scenario,which is the most correct?

A) This is a mistake of law,specifically the law of contract.
B) This is a mistake of fact.
C) This is an example of a mistake of utmost good faith.
D) This is a case of innocent misrepresentation.
E) This is a mistake about the existence of the subject-matter of the contract.