Microsoft sells Windows for $300 cash. The purchase price includes the software as well as access to telephone support and upgrades for the next three years. The undelivered elements represent 10% of the purchase price on average. The journal entry that Microsoft records at the time of sale includes: A. A credit to revenue for $300 B. A credit to cash for $300 C. A credit to unearned revenue for $300 D. A credit to revenue for $30 and a credit to unearned revenue for $270 E. A credit to revenue for $270 and a credit to unearned revenue for $30. F. A debit to contra revenue for $30 and a debit to cash for $270.