V. Choose the option (A, B, or C) that best completes each numbered blank in the passage.

In Viet Nam nowadays, most companies spend a large proportion of their budgets persuading US to buy their products, and it is their (26) __________ executives who have to decide how to make consumers aware of new products. To do this, they usually set up an advertising (27) __________ of some kind. Generally (28) __________ a new product involves TV and radio commercials, and there may also be large advertisements on (29) __________ along motorways and major roads. In the past, companies employed people to sell the product (30) __________ but nowadays there is a far more popular technique which uses the telephone. Staff in large call centers telephone potential (31) __________ tell them about the product and try to convince them that it is worth buying. Another technique is to (32) the new product by post. The company sends colourful (33) __________ to every house even though people haven’t asked for them. They are so unpopular that people call them (34) __________ mail - and even though they may contain free (35) __________ or discount vouchers, many people just put them straight into the rubbish bin!