Answer:
a. An audit adjustment is needed since the best case scenario, where the net realizable value is highest would result in $92,000 - $5,000 = $87,000.
b. the value of inventory must decerase by $99,000 - $87,000 = $12,000, so COGS must increase by that amount:
Dr Cost of goods sold 12,000
Cr Merchandise inventory 12,000