Some of the customers of Casey Corporation pay in advance for services, and others pay after the services have been performed. At January 1, 2018, the firm's accounts receivable were $860,800, and the balance in Unearned Revenue was $640,000. At December 31, 2018, the adjusted balance in accounts receivable was $892,800. For the year ended December 31, 2018, accrual-basis revenues were $1,122,400, and the total amount of cash collected from customers was $1,275,200. What was the ending balance in Unearned Revenue? a. $760,800 b. $792,800 c. $824,800 d. $856,800 e. $879,800