The correct answer is A) Nagarjuna Sagar.
Nagarjuna Sagar Dam is a gravity dam on the Krishna River located in Nalgonda district of Telangana, India. It is the second largest dam in India after the Bhakra Dam. The dam was constructed between 1955 and 1969 and is named after Nagarjuna, a Buddhist philosopher and teacher who lived in the 2nd century CE.
The dam has a height of 124 meters (407 ft) and a length of 1,960 meters (6,430 ft). It has a storage capacity of 80.6 tmcft (2.8 billion cubic meters) and a live storage capacity of 63.2 tmcft (2.2 billion cubic meters). The dam generates 880 MW of hydroelectric power.
The Nagarjuna Sagar Dam has a number of benefits, including flood control, irrigation, drinking water supply, and hydroelectric power generation. However, it has also had a number of negative impacts, including the displacement of thousands of people, the loss of biodiversity, and the siltation of the reservoir.
The other options are incorrect because they are not major hydel power projects located on the Krishna River in Telangana.
Option B, Srisailam Dam, is a hydroelectric dam on the Krishna River located in Kurnool district of Andhra Pradesh. It is the third largest dam in India after the Bhakra Dam and the Nagarjuna Sagar Dam. The dam was constructed between 1960 and 1980 and is named after Srisailam, a Hindu pilgrimage site located nearby.
Option C, Nizam Sagar Dam, is a hydroelectric dam on the Krishna River located in Adilabad district of Telangana. It was constructed between 1903 and 1909 and is named after Mir Osman Ali Khan, the seventh Nizam of Hyderabad.
Option D, Jurala Dam, is a hydroelectric dam on the Krishna River located in Karimnagar district of Telangana. It was constructed between 1953 and 1959 and is named after Jurala, a village located nearby.