Please answer and help me understand A, B and C. Thank you!

Sales-Related Transactions, Including the Use of Credit Cards Illustrate the effects on the accounts and financial statements of recording the following transactions. If no account or activity is affected, select "No effect" from the dropdown and leave the corresponding number entry box blank. a. Sold merchandise for cash, $62,500. The cost of the goods sold was $30,000. Balance Sheet Statement of Income Assets = Liabilities + Stockholders' Equity Cash Flows Statement Cash + Inventory = No Effect + Retained Earnings 62,500 0 32,500 Statement of Cash Flows Income Statement Operating Cost of goods sold 30,000 b. Sold merchandise on account, $27,800. The cost of the goods sold was $16,000. Balance Sheet Statement Income of Cash Assets = Liabilities + Stockholders' Equity Statement Flows Accounts Receivable + Inventory No Effect + Retained Earnings 27,800 11,800 Income Statement c. Sold merchandise to customers who used MasterCard and VISA, $287,500. The cost of the merchandise sold was $170,000. Balance Sheet Statement of Income Assets Liabilities + Stockholders' Equity Cash Flows Statement Cash + Inventory = No Effect + Retained Earnings 287,500 170,000 0 117,500 Statement of Cash Flows Income Statement Operating