下列存储器从存取速度看，由快到慢依次是_____________。
A、内存、Cache、光盘和硬盘
B、内存、Cache、硬盘和光盘
C、Cache、内存、光盘和硬盘   
D、Cache、内存、硬盘和光盘

A．derived because it is determined by the demand for international purchases.
B．relative because it is determined by exogenous variables.
C．derived because demand is a function of the government's intervention in currency markets.
D．linear because it is determined by forces that move so quickly.