某建筑材料采购合同，既约定了违约金，又约定了定金。当一方违约时，守约方( )。

A．必须适用违约金条款
B．必须适用定金条款
C．可以选择适用违约金或定金条款
D．两者都不能适用，因约定无效

She________Japanese when she was in Japan. Now she can speak it freely. [ ]

A. picked out  

B. made out

C. made up  

D. picked up