For each separate case, record the necessary adjusting entry. 

a. On July 1, Lopez Company paid $1,200 for six months of insurance coverage. No adjustments have been made to the Prepaid Insurance account, and it is now December 31. Prepare the year-end adjusting entry to reflect expiration of the insurance as of December 31. 

b. Zim Company has a Supplies account balance of $5,000 at the beginning of the year. During the year, it purchases $2,000 of supplies. As of December 31, a physical count of supplies shows $800 of supplies available. Prepare the adjusting journal entry to correctly report the balance of the Supplies account and the Supplies Expense account as of December 31.