The question asks to identify the locations that are famous for Sun temples out of the given options.

Option 1, Arasavalli, is the correct choice as Arasavalli, located in Andhra Pradesh, is famous for a Sun temple known as the Suryanarayana Temple. It is one of the few Sun temples in India.

Option 2, Amarkantak, is incorrect as Amarkantak, situated in Madhya Pradesh, is known for its temples but not specifically Sun temples. The primary attractions in Amarkantak are Shri Yantra Mandir and Narmada Udgam.

Option 3, Omkareshwar, is also an incorrect option as Omkareshwar, located in Madhya Pradesh, is well-known for the Omkareshwar Temple, an important center for Shiva worship, not a Sun temple.

So, only Arasavalli among the given options is associated with a Sun temple, which makes Option 1 – `1 only` – the correct answer.