What is correct in respect of the term "chaityas" in the context of Buddhism.

Sites with special trees or unique rocks, or sites of awe-inspiring natural beauty and having small shrines attached to them, were sometimes described as chaityas. Chaitya may also have been derived from the word chita, meaning a funeral pyre, and by extension a funerary mound. Buddhist literature mentions several chaityas. All of the above.

All of the above.

From earliest times, people tended to regard certain places as sacred. These included sites with special trees or unique rocks, or sites of awe inspiring natural beauty. These sites, with small shrines attached to them, were sometimes described as chaityas. Buddhist literature mentions several chaityas. It also describes places associated with the Buddha’s life – where he was born (Lumbini), where he attained enlightenment (Bodh Gaya), where he gave his first sermon (Sarnath) and where he attained nibbana (Kusinagara). Gradually, each of these places came to be regarded as sacred. About 200 years after the time of the Buddha, Asoka erected a pillar at Lumbini to mark the fact that he had visited the place. Chaitya may also have been derived from the word chita, meaning a funeral pyre, and by extension a funerary mound.