A deposit for Julie A. Smith at the local bank was inadvertently recorded as a de- posit in the account of June A. Smith. The control that would most likely have detected the error in depositing the amount to the wrong account would be:

a. The use of self-checking digits on account numbers.

b. Range tests on accounts in which the deposit is related to the size of the account.

c. Limit tests.

d. Validity tests to determine whether Julie Smith is a valid customer.