Which of the following types of intrusion techniques is the use of an "under-the-door tool" during a physical security assessment an example of?

Lockpicking involves inserting tension wrenches and picks into the lock cylinder to manipulate internal pins or wafers to replicate the correct key, which is a direct attack on the locking mechanism itself.

Egress sensor triggering exploits motion-activated or pressure-sensitive electronic door-release mechanisms near exits, not a physical door handle or lock cylinder.

Lock bumping uses a specially cut bump key inserted into a pin tumbler lock that is struck to momentarily displace the driver pins above the shear line, which is a direct mechanical attack on the lock cylinder.

Lock bypass describes techniques that circumvent a locking mechanism without picking or bumping it. The under-the-door tool is inserted beneath the door gap to pull down an interior lever handle from the outside, completely avoiding the lock cylinder. The lock is never engaged or attacked - the physical barrier is simply worked around using the interior release hardware.