In which year was ‘Sanchi’ declared a World Heritage Site?

The correct answer is Option (1) → 1989

The great stupa at Sanchi is one of the most famous Buddhist monuments of early India. After more than a century of exploration, publication and conservation, from Cunningham’s Bhilsa Topes (1854) to John Marshall’s work in the twentieth century, Sanchi was declared a World Heritage Site in 1989.

This year sits on the very last line of the chapter’s timeline. NTA reads timelines to the bottom, so read them to the bottom too.

Note: A same/similar question was asked in CUET (UG) in the papers below.

* A similar question.