Which exploit builds its attack around “half-open” connections?

Which exploit builds its attack around "half-open" connections?

A.
Ping flooding

B.
SYN flooding

C.
Trojan horses

D.
Worms

Explanation:
SYN flood is when an attacker sends a victim several SYN packets with spoofedsource addresses. Each time the victim receives a SYN packet, it will set upresources for a connection. The connections are never fully built because the victimnever receives the ACK packets from the attacker. This is why it is referred to as a"half-open" connection attack.