Which of the Following Is Not True with Regard to Lock

Which of the following is not true with regard to lock and key systems?

A) The locking system should be supplemented with other security devices.
B) Most key locks can be picked by an expert in a few minutes.
C) A high-quality pickproof lock is considered a positive bar to entry.
D) The lock is the most accepted and widely used security device of the basic safeguards in protecting installations.
E) Locks, regardless of quality or cost, should be considered as delay devices only.