【正确答案】 C

【答案解析】[听力原文]
Rona: Hello. May I speak to Mr. Phillips in the Sales Department?
Phillips: Phillips speaking.
Rona: Hello, Mr. Phillips. This is Rona Waters from Field Wholesale Electricals.
Phillips: Rona, how are you?
Rona: Fine. The reason I"m calling is we need to sort out a final price on the coffee machines.
Phillips: Of course. What did we want to charge you?
Rona: Well, you gave us a unit price of $30.
Phillips: That"s right. Are you happy with that?
Rona: It depends. We intend to purchase about 150 to 200 a month. So we were wondering what sort of quantity discount you can offer us?
Phillips: I see. Just a moment. I"ll check my tables... Well, at an order quantity of 200, we would be willing to offer you a 10 per cent discount.
Rona: So that"ll bring down the unit price to $27.
Phillips: That"s right...a very favorable price.
Rona: Uhum... What about larger quantities—for example, what about putting in a quantity order of around 500?
Phillips: Well, I don"t have any figures for those sorts of quantities, but I know we"ve got one customer who gets 15 percent on 500.
Rona: I see, so that would be... er... $25.5 per unit?
Phillips: Correct, I"d have to confirm that.
Rona: Sure, I understand.
Phillips: There"s another point to mention which is payment terms. Would you be interested in a discount for early payment?
Rona: What sort of figure do you have in mind?
Phillips: Well, we"re prepared to offer two percent for payment within fifteen days. Our normal terms are thirty days.
Rona: Interesting. I"ll have to get back to you on that.
Phillips: Right. We"ll be in touch. Goodbye.
Rona: Bye.

What is the regular unit price of a coffee machine?