LIGO stands for Laser Interferometer Gravitational wave Observatory. The correct answer is option 1.

Option 1: Laser Interferometer Gravitational wave Observatory - This is the correct answer. LIGO is a large-scale scientific experiment and observatory used to detect gravitational waves. It uses highly sensitive laser interferometers to measure tiny ripples in the fabric of space-time caused by the collision of massive celestial objects.

Option 2: Light Interferometer Gravitational wave Observatory - This option is incorrect. While the use of light interferometers is a part of LIGO, the correct acronym is Laser Interferometer Gravitational wave Observatory.

Option 3: Light Induced Gravity Observatory - This option is incorrect. LIGO does not observe or study light-induced gravity. It specifically focuses on gravitational waves.

Option 4: Laser Induced Gaseous Optics - This option is incorrect. LIGO does not involve studying gaseous optics or laser-induced phenomena. Its main purpose is to detect gravitational waves using laser interferometers.