Answer :
In partially restricted systems, the main entrance may remain d. unlocked while other doors remain locked.
In partially restricted systems, the term 'main entrance' typically refers to a primary access point that may be accessible or easier to access (hence 'unlocked'), while other secondary access points or doors remain secured (hence 'locked').
This arrangement ensures controlled access, facilitating the movement of authorized entities through the main entrance while restricting unauthorized movement via other doors.
