A penetration tester is testing the security of a building’s alarm system.

Testing the security of a building's alarm system falls under physical penetration testing. According to Security+ SY0-701, physical penetration tests evaluate the effectiveness of physical security controls such as locks, alarms, cameras, sensors, badge readers, and access control points. These tests simulate real-world attempts to bypass or disable physical protections.

Defensive testing (B) refers to defensive security operations, not pen testing scope. Integrated testing (C) relates to combined system evaluations but is not a standard pen testing category. Continuous testing (D) refers to ongoing automated tests, not physical alarm evaluation.

Thus, the correct answer is A: Physical.