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