What advantage does the crest provide in a reverse slope defense?

In a reverse slope defense, positioning troops behind the crest of a hill allows them to take advantage of the natural terrain for protection against direct fire from the enemy. By being positioned out of the line of sight from an attacking force on the forward slope, troops can remain concealed while still being able to observe and engage the enemy effectively. This setup minimizes the risk of being targeted by direct fire weapons, such as artillery or small arms, as the crest serves as a shield.

While other options detail aspects related to troop mobility, logistical needs, or aerial support, they do not fundamentally capture the critical protective advantage that the crest provides against the immediate threat of enemy fire, which is essential in a defensive strategy. Ensuring safety from direct fire is a primary concern during any military engagement, particularly in a defensive posture where maintaining the integrity of the unit is a priority.