问题：

[单选] The classic Spanning Tree Protocol （802.1 D 1998） uses which sequence of variables to determine thebest received BPDU？（）

A . 1） lowest root bridge id，2） lowest sender bridge id，3） lowest port id，4） lowest root path cost
B . 1） lowest root path cost，2） lowest root bridge id，3） lowest sender bridge id，4） lowest sender port id
C . 1） lowest root bridge id，2） lowest sender bridge id，3） lowest root path cost，4） lowest sender port id
D . 1） lowest root bridge id，2） lowest root path cost，3） lowest sender bridge id，4） lowest sender port id