Ace Manufacturing, Inc., has property insurance with National Insurer, Inc. When Ace suffers a loss in a burglary, Ace and National cannot agree on the amount of recovery. Under an appraisal clause,

a. only Ace can demand an appraisal by a third party.

b. only National can demand an appraisal by a third party.

c. either party can demand an appraisal by a third party.

d. the government sets the value of the loss, which both parties must accept.