Consider the following events for Sophia Incorporated: April 5 Sophia purchases volleyballs for $200 on account. April 6 Sophia advertises a sand volleyball camp for $20 a person. April 12 Thirty people sign up for the camp paying a total of $600. April 21 Sophia hosts the sand volleyball camp. April 23 Sophia pays for the volleyballs purchased on April 5.Under cash-basis accounting, what is the appropriate day to record the expenses related to the sand volleyball camp?