The space agency that sent 104 satellites in a single mission in 2017 is the Indian Space Research Organisation (ISRO). The correct answer is (C) ISRO. ISRO's Polar Satellite Launch Vehicle (PSLV-C37) set a record by launching 104 satellites in a single mission on February 15, 2017.

The Rawatbhata Nuclear Power Plant is located in Rawatbhata, a town in the Chittorgarh district of the Indian state of Rajasthan. It is a complex that houses several nuclear reactors, including pressurized heavy water reactors (PHWR) and pressurized heavy water reactors of the Indian design. The plant plays a significant role in contributing to the electricity generation capacity of the region and the country.

A. H. Taylor and Leo C. Young were American scientists who played a crucial role in the development of radar technology. They are credited with creating the first radar system in the United States. Radar, which stands for "Radio Detection and Ranging," is a technology that uses radio waves to detect and locate objects. It became essential during World War II for various applications, including aircraft detection and navigation. The work of Taylor and Young contributed significantly to the advancement of radar technology and its subsequent widespread use in military and civilian applications.