Selected Answer: A If the interface gets 16 back-to-back collisions while a frame is being transmitted, it gives up and the frame is dropped. This kind of collision is called Excessive Collision.

A is definitely right, my bad

I see here that the maximum number of retries in the backoff algorithm is set to 16, so A may be the right answer https://www.cisco.com/c/en/us/support/docs/interfaces-modules/port-adapters/12768-eth-collisions.html

Selected Answer: A The retransmission algorithm helps make sure packets do not retransmit at the same time. However, if the two devices retry at almost the same time, packets can collide again; the process keeps repeating until either the packets eventually get onto the network without collisions, or 16 consecutive collisions happen and the packets are discarded.

Selected Answer: C The exhibit shows that collisions are occuring. Collisions produce runts (frames lower than 64 bytes). So the correct answer is C. There is nothing in the exhibit to show that frames are dropped after 16 failed transmission attempts, only that there are many collisions happening.