For each of the following independent situations, prepare journal entries to record the initial transaction on December 31 and the adjustment required on January 31. (If no entry is required for a transaction/event, select "No Journal Entry Required" in the first account field.)

a. Magnificent Magazines received $12,600 on December 31, 2015, for subscription services related to magazines that will be published and distributed in January through December 2016.

b. Walker Window Washing paid $1,260 cash for supplies on December 31, 2015. As of January 31, 2016, $210 of these supplies had been used up.

c. Indoor Raceway received $3,150 on December 31, 2015, from race participants for providing services for three races. One race is held in January 31, 2016, and the other two will be held in March 2016.

1. Record the receipt of $12,600 on December 31, 2015, for subscription services related to magazines that will be published and distributed from January through December 2016.

2. Record the January 31, 2016 adjusting entry for the December 31, 2015 receipt of $12,600 for magazine subscriptions to be published January through December 2016.

3 .Record the payment of $1,260 cash for supplies by Walker Window Washing on December 31, 2015. As of January 31, 2016, $210 of these supplies had been used up.

4. Record the January 31, 2016 adjusting entry for the December 31, 2015 cash payment of $1,260 for supplies. As of January 31, 2016, $210 of these supplies had been used up.

5 .Record the receipt by Indoor Raceway of $3,150 on December 31, 2015, from race participants for providing services for three races. One race is held on January 31, 2016, and the other two will be held in March 2016.

6. Record the January 31, 2016 adjusting entry for the December 31, 2015 receipt of $3,150 from race participants for providing services for three races. One race is held on January 31, 2016 and the other two will be held in March 2016.