Correct Answers & Explanations:B, and
B is correct, because a hub increases collisions on your network. When you use hubs on your network, all of them use shared media. Answer
D is correct, because when a hub sends traffic it does this to all ports except the originating port.
Incorrect Answers & Explanations:A, and
A is incorrect, because a hub works at the physical layer. Answer
C is incorrect, because hubs don't work with MAC addresses.