The Fact That Two Consecutive Doors Cannot Be Opened at the Same

The fact that two consecutive doors cannot be opened at the same time in a correctional facility illustrates how:

A) Security is built into physical design
B) Treatment and custody must cooperate to prevent escapes
C) It is necessary to prevent the corrupt alliance between officers and inmates
D) Two officers are posted at the entrance to certain critical doors
E) Little the administration trusts correctional officers