Final answer:
The goal of a perimeter protection system, which is indeed true, is to deter intruders and detect any unauthorized entry, acting as the first line of defense against potential threats.
Step-by-step explanation:
The statement that the goal of a perimeter protection system is to make it difficult for an intruder to enter and to detect an intruder if they make entry is true. An effective perimeter protection system serves as the First Line of Defense, much like the moat and walls around a castle. Its objective is two-fold: first, to deter potential intruders by making it challenging to breach the perimeter, and second, to detect and alert the presence of intruders should they attempt to or succeed in entering.