Correct Option (a):
The Guru Shikhar Peak is located in Rajasthan. It is the highest peak of the Aravalli Range and the highest point in the state of Rajasthan, with an elevation of 1,722 meters above sea level. The peak is situated in the Sirohi district, near the hill station of Mount Abu. It is named after Sage Dattatreya, to whom a temple is dedicated at its summit. The site also houses the Guru Shikhar Observatory, operated by the Physical Research Laboratory for infrared astronomy and atmospheric studies.
Incorrect Options:
(b) Gujarat: While Mount Abu is situated close to the Gujarat border, Guru Shikhar itself lies entirely within Rajasthan.
(c) Madhya Pradesh: The highest point in Madhya Pradesh is Dhupgarh Peak, located in the Satpura Range, with an elevation of 1,350 meters.
(d) Maharashtra: The highest peak in Maharashtra is Kalsubai, situated in the Western Ghats, rising to an elevation of 1,646 meters.