While capturing network traffic, you notice an excessive amount of traffic destined to a particular host on TCP port $25.$ What is one possible explanation for this?

Question $4$Answer

a$.$

A mail server is being flooded with spam.

b$.$

A network broadcast attack is taking place.

c$.$

Users$$ devices on the network happen to be issuing DNS queries at the same time.

d$.$

A web server is experiencing a large volume of concurrent visitors.