Not that I’m unwilling to lend you a hand I’m too busy for the moment .A. because B. but

问题补充：

Not that I’m unwilling to lend you a hand ,I’m too busy for the moment .

A. because

B. but that

C. but

D. however

答案：

A. because

B. but that

C. but

D. however

解析：not that…，but that…不是….，而是…。不是我不愿帮你，而是我目前太忙了。故选B。