Which of the following infractions incurs a 5-yard penalty during free kicks?

The option indicating that all of the listed infractions incur a 5-yard penalty during free kicks is correct because it encompasses several scenarios that the NFHS rules identify as deserving of a 5-yard enforcement.

A snap infraction, typically involving illegal actions by players during the snapping process, results in a 5-yard penalty, and this applies regardless of whether it occurs before, during, or after the snap on a free kick.

An illegal formation occurs when the kicking team is not properly aligned according to the formation rules before a free kick. This infraction is also subject to a 5-yard penalty, affecting the team's ability to execute the kick properly.

Furthermore, if a free kick goes out of bounds without being touched by a player, the kicking team can face a 5-yard penalty. This is outlined in the rules which stipulate that a team must execute its kicks legally, and if not, any violation associated with this situation results in a 5-yard enforcement.

Each of these infractions has a consistent penalty application under NFHS rules during free kicks, hence the correct answer reflects that they all incur a 5-yard penalty.