Which two statements regarding the Snort rule header are false? $($Choose two.$)$

The rule header determines which Snort rules run against the traffic sent to the respective IPS policy.

The rule header must contain variables for the network and ports.

The SID is identified within the rule header.

All Snort rules contain a rule header specifying variables, except for rules with a GID of $100$ or above or custom rules.

The rule header definitions can be changed by modifying the variable definitions.