Sun Corporation (Sun) is engaged in purchases and sales of reusable drinking bottles. The company adopts perpetual inventory system to record inventory and costs of sales. Besides, the company records purchases of goods at gross invoice price. The following information was extracted from the unadjusted trial balance dated on 30 November 2020: Dr. (S) Cr. (S) 2,500,000 Sales Sales returns and allowances Cost of goods sold Sales discounts Inventory 5,000 1,580,000 10,000 258,000 Moon Corporation (Moon), one of the major customers of Sun Corporation, is engaged in exporting reusable drinking bottles to Malaysia. Periodic inventory system is adopted. Besides, the company records purchases of goods at gross invoice price. For any returns on purchase, the company will record in "Purchases returns account. The following transactions occurred in December 2020: Dec 2 Dec 3 Dec 4 Sun purchased $400,000 plastic bottles from its supplier with credit term 1/15, n/30. Sun returned $10,000 plastic bottles, purchased on 2 December, with full credit as the bottles' color is not correct. Sun sold $500,000 plastic bottles to Moon with credit term 2/10, n/30. The gross profit rate is 20%. Moon returned $5,000 incorrect products purchased on 4 December to Sun with full credit Sun sold $100,000 plastic bottles to Moon in cash. The gross profit rate is 25%. Dec 10 Dec 11 Dec 12 Sun received a check from Moon regarding to credit sale in December. Dec 22 Sun settled the outstanding balance in full regarding to the purchase in December. Dec 31 Sun conducted physical count and revealed $160,000 inventory was on hand. Required: a) Prepare journal entries for Sun Corporation regarding to the above transactions in December (23 marks) b) Prepare Partial Income Statement of Sun Corporation for the year ended 31 December 2020 to show gross profit of the year