The correct answer is option 4, Moon. The Moon is not a luminous object because it does not emit its own light. Instead, it reflects the light of the Sun. Luminous objects are those that produce and emit their own light.

Option 1, Sun, is a luminous object. It is a star that emits a vast amount of light and heat through the process of nuclear fusion.

Option 2, Electric lamp, is also a luminous object. It produces light by converting electrical energy into light energy using a filament or LED.

Option 3, Candle, is another luminous object. It produces light through the combustion of wax or similar material with a wick.

However, it is important to note that the Moon can still appear bright in the night sky due to the Sun`s light reflecting off its surface. The Moon acts as a reflector of light rather than a source of light.