What type of scan is Winston attempting here?

To see how some of the hosts on your network react, Winston sends out SYN packets to an IP
range. A number of IPs respond with a SYN/ACK response. Before the connection is established
he sends RST packets to those hosts to stop the session. Winston has done this to see how his
intrusion detection system will log the traffic. What type of scan is Winston attempting here?

A.
Winston is attempting to find live hosts on your company’s network by using an XMAS scan.

B.
He is utilizing a SYN scan to find live hosts that are listening on your network.

C.
This type of scan he is using is called a NULL scan.

D.
He is using a half-open scan to find live hosts on your network.