Which of the following statements is not true regarding distributed denial of service $($DDoS$)$ attacks?

A$.$Attacks of this type use hundreds or thousands of systems to conduct the attack.

B$.$Defense is difficult due to the number of attacker sources.

C$.$The attack is easily tracked back to its true source.

D$.$The impact of this attack is increased over that of a standard denial of service $($DoS$)$ attack.