Which of the following is an advantage of a PLC?

• A. High initial cost
• B. Highly reliable, Highly versatile (universal applicability), Simple troubleshooting
• C. Sensitive to dust, high temperature and high humidity
• D. No moving parts

Answer: (B)

The question tests what practical benefits a PLC brings to industrial control. A PLC is a rugged, solid-state controller designed for harsh environments, which makes it highly reliable due to minimal mechanical wear and built-in diagnostics. Its programmability gives it broad versatility: you can configure it for many different processes and update behavior without changing hardware, just by rewriting the program. And the way it presents status, allows ladder-logic debugging, and provides modular I/O and clear diagnostics makes troubleshooting much simpler. While no moving parts is also true of a PLC, the answer that best captures the everyday value engineers look for is the mix of high reliability, broad applicability, and easier troubleshooting.