If, Even if, Unless, Though

[25Hrs/Day]

Please help me with this multiple choice. I don't just want the answer, actually I have the key, which is X (will tell you later). I hope you can give me your reasons why it's correct or why IT'S NOT CORRECT. Thanks a million.


_____ he promises to lend us plenty of money, I won't start up my own business.
A. If　　　　B. Even if　　　　C. Unless　　　　 D.Though

[Tdol]

Because it makes sense logically. The others could only work if you wanted to take the money and have no business and if the person wanted to stop you having the business. The logical choice is to borrow money to start a business.