What does ‘Chaitya’ in Buddhist architecture refer to?

Prayer hall

The correct answer is Option (2) → Prayer hall

In Buddhist architecture, 'Chaitya' refers to a Buddhist shrine or prayer hall. These structures are often characterized by a stupa or a domed structure that houses relics or sacred objects. Chaityas are important places of worship and meditation for Buddhists, and they are often adorned with intricate carvings and decorations.