I bought the bag for ten dollars. 我花10美元买了这个包。 (《外研社英汉多功能词典》p.281)
I paid ＄50 for the hat. 我花了50美元买了这顶帽子。(《外研社英汉多功能词典》p.1540)
The bicycle is not worth what you paid for it. 这自行车不值你付的那些钱。（赵振才教授编著《英语常见问题解答大词典》增订版 p.1660）
从这三个句子的结构来看，应该是“买它的钱”，what you paid for it = what you bought it for, 所以正确答案应该是 A（what you bought it for）。

同意罗老师和黎老师的解析，是我粗心看错了，向位朋友致歉！

COCA上的例句：But the uncertainty over the FDA's move and the potential for development make it difficult to put a value on the land, Kyle said. " It's worth what somebody will pay for it. It's that basic. "

I think I'm worth what I'm being paid, " said Woodill, 49, who said his salary of more than $ 100,000 makes him one of the highest-paid people in the merchant marine.

What you're going to get is not going to be worth what you spent. It's as simple as that.

No one argues that lawyers should be compelled to work for free, but the public questions whether legal services, and the results they yield, are worth what they cost.

He asked me,' How much do you think it's worth?' It's worth what people will pay for it. Some people will pay more than others. It's really difficult to say what the values of the games are.

I don't know. It's like they said, it's worth what they want to pay for it. I mean, if I had money to burn, I suppose I would buy the golf clubs for about a million bucks, just so that I could annoy the 30 million golfers who wished they had it.

What is that worth? It's worth what somebody's willing to pay for it, and we're going to find out next week what it is.

Well look out there. You can't see. It's dark and there's seven acres of woods around here. A lot can happen. It's dangerous. It's not worth what they pay you.

So high are the stakes, so urgent the occasion, so weighty the outcome, that disciplined learning is worth what it costs, which is most of our time, most of the year, for most of our lives.

" I've never met a player yet who didn't feel he was worth what he was paid, " McCombs says with a chuckle.

But none of this takes away from the charger's usefulness or its decorative value. It is certainly worth what you paid for it!

Now those owners may start to feel the pinch. Those who bought the biggest house possible, especially in the past year, may soon be worrying that the house isn't worth what they paid for it, Paulsen said.

Does counterinsurgency work? " Yes,' he said. " Is it worth what you paid for it? That's an entirely different question. "

从以上可以分析出A是正确的，B，C，D是错误的。