Lumen is the unit used to measure the luminous flux or total amount of visible light emitted by a source. It quantifies brightness and is crucial in lighting design for security applications.
A (Pixel) relates to image resolution.
B (Watt) measures energy consumption, not light output.
D (Fresnel) refers to a type of lens used to focus or direct light.
References:
PSP Study Guide - Lighting Measurement and Application
POA Manual - Lighting Design for Security

Risk spreading refers to decentralizing operations or distributing assets so that if one site or operation is compromised, the entire organization isn't paralyzed. For example, backing up data across multiple locations ensures that the loss of one system doesn't cause total data loss.
References from PSP: Risk Management Techniques - ASIS POA; PSP Certification Guide - Business Resilience Measures

A comprehensive contingency planning program consists of:
Emergency Response: Immediate actions during a crisis to protect life and property.
Crisis Management: Command structure and coordination during an event.
Business Continuity: Efforts to maintain or quickly restore essential functions.
Together, these components form a resilient framework for organizational preparedness.
References:
ASIS POA Manual - Contingency and Continuity Planning
PSP Study Guide - Emergency Preparedness and Crisis Response

Proprietary security services are those in which the security personnel are hired, trained, and managed directly by the organization they protect. They are part of the company's staff and are not outsourced from external firms. Proprietary security typically ensures tighter integration with company culture and policies and offers better control over personnel and procedures.
Contract security services (Answer D) involve third-party firms providing personnel who are not employees of the protected organization.
Security enforcement (Answer B) is a general term, not a specific classification.
Pilferage (Answer C) refers to theft and is unrelated to service type.
References:
ASIS International, Protection of Assets (POA) Manual - Chapter on Security Personnel PSP Study Guide, Domain 3: Implementation of Physical Security Measures

For confined interior areas containing explosive vapors or materials, non-emitting sensors are preferred to avoid ignition risk. Passive Infrared (PIR) sensors are ideal in such environments because they detect heat signatures (infrared energy) emitted by intruders without emitting any signals or energy that could trigger an explosion.
A (Ultrasonic) and C (Capacitance) sensors emit signals.
D (Passive vibration sensors) detect vibration and are used in a different context, like surface tampering.
References:
PSP Study Guide - Intrusion Detection Systems and Safety Considerations POA Manual - Sensor Selection for Hazardous Environments