Suppose that you want to write a program that inputs customer data including name, zipCode, balance, and regionNum. At the end of the program, a summary of the number of customers in each of 12 sales regions who owe more than $1000 each is displayed. The most likely statement during the main processing loop would be _____________.

a. customerCount[balance] = customerCount[balance] + 1

b. customerCount[regionNum] = customerCount[regionNum] + 1

c. customerCount[regionNum] = regionNum - 1

d. customerCount[balance] = balance + customerCount[regionNum]