Why did this ping sweep only produce a few responses?

Lauren is performing a network audit for her entire company. The entire network is comprised of
around 500 computers. Lauren starts an ICMP ping sweep by sending one IP packet to the
broadcast address of the network, but only receives responses from around five hosts. Why did
this ping sweep only produce a few responses?

A.
Only Windows systems will reply to this scan.

B.
A switched network will not respond to packets sent to the broadcast address.

C.
Only Linux and Unix-like (Non-Windows) systems will reply to this scan.

D.
Only servers will reply to this scan.