Which of the following is an inert gas most commonly found in light bulbs?

Argon

The correct answer is option 1. Argon.

The inert gas most commonly found in light bulbs is Argon.

Argon is often used in incandescent light bulbs to fill the empty space inside the bulb. It helps prevent the filament from oxidizing at high temperatures, thereby prolonging the life of the bulb. Additionally, argon aids in reducing filament evaporation, contributing to the overall efficiency and longevity of the bulb.