Hampi was declared a World Heritage Site by UNESCO in the year:

1986

The correct answer is Option (3) → 1986

Hampi was declared a UNESCO World Heritage Site in 1986.

Timeline related to Hampi:

• The ruins at Hampi were brought to light in 1800 by an engineer and antiquarian named Colonel Colin Mackenzie.
• In 1856 Alexander Greenlaw takes the first detailed photographs of archaeological remains at Hampi.
• In 1976, Hampi was recognized as a site of national importance.
• In 1986 Hampi was declared a World Heritage site by UNESCO.