can someone explain this one?

ABC Manufacturing ("ABC") has a December 31,2020 year-end. Tools returned by customers and held pending inspection in the returned goods area on December 31 , 2020 , were not included in the physical count. On January 8, 2021, the tools costing $50,000 were inspected and returned to inventory. Credit memos totaling $63,000 were issued to the customers on the same date. At December 31,2020 , what adjustment(s), if any, should be made to ABC 's books? Increase inventory by $50,000 and increase net sales by $63,000. Decrease inventory by $50,000 and decrease net sales by $63,000. Increase inventory by $50,000 and decrease net sales by $63,000 None of the above