问一个JJ的题目~谢谢~

roy0532

非限定性定语从句
   还有比较 XXX is cost half or even less __后面的东西划线__the last year
   A than
   B than what it was cost
   C of what it was 之类的吧
纠结A和B啊~A更简洁...B好像更对称...请教哪一个对捏？谢谢大家哈~