In order to obtain the needed information, the inquirer should simply, clearly and concisely write _____ he wants to know. A: that B: so C: what D: because of

It is strongly advisable that when replying to an inquiry, the seller starts his letter by( ). A: providing details of the product B: thanking the inquirer for his interest C: telling honestly that the product is out of stock D: directly informing about the prices