Which best describe the mechanism of a TCP SYN flood?

A.
The attacker keeps open many connections with slow data transmission so that other clients cannot start new connections.

B.
The attacker sends a packet designed to “sync” with the FortiGate.

C.
The attacker sends a specially crafted malformed packet, intended to crash the target by exploiting its parser.

D.
The attacker starts many connections, but never acknowledges to fully form them.