The classic Spanning Tree Protocol （802.1D 1998） uses which sequence of variables to determine the best 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）owest sender port id

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