Which statement about Class B SLC are true?

• A. They are permitted to be tapped.
• B. They cannot be tapped.
• C. They require shielded cable.
• D. They are irrelevant to alarm circuits.

Answer: (A)

Signaling Line Circuits are wired in ways that determine how devices can be added and still stay supervised. In Class B, devices are connected along a single linear path from the panel to the last device, and it is permitted to tap into that trunk to add additional devices as the system grows. This ability to tap makes expansion practical without forcing a move to a different circuit class, while the end-of-line and supervision remain intact when done correctly. Keep in mind that any taps must be installed per the applicable standards to maintain proper impedance and supervision; the other statements—saying taps aren’t allowed, requiring shielded cable, or being irrelevant to alarm circuits—do not fit the actual wiring approach for Class B SLC.