The access mode of elements in the priority queue is:优先级队列中元素的访问模式是：
- 未答复

A．Smaller rank one is firstly visited.秩小者先访问
B．Bigger rank one is firstly visited.秩大者先访问
C．Higher priority one is firstly visited.
优先级高者先访问
D．Front-located element is firstly visited位置靠前者先访问