Concept:Devices that use magnetic effects, such as attraction, repulsion, or electromagnets, operate on magnetism.
Solution:Loudspeakers use an electromagnet interacting with a permanent magnet to produce sound.
Compasses rely on a magnetic needle aligning with the Earth’s magnetic field.
Alarms commonly use magnetic switches or electromagnets to produce alerts.
LCD TV works on liquid crystal display technology, not magnetism, so every set containing an LCD TV is wrong.
Key point: The paper printed options C and D the same (Compass, loudspeakers, LCD TV); option D has been corrected to a distinct set. Only option A has no LCD TV.
Answer:Option A (Loudspeakers, compass, alarms)