Answer: Option A. -> EDSAC
Answer: (a)
EDSAC is The first computer used to store a program.
It was subsequently developed into the Manchester Mark 1, which ran its first program in early April 1949. Electronic Delay Storage Automatic Calculator, EDSAC, became fully operational providing a service to a range of customers on May 6, 1949.
The Manchester Baby, also known as the Small-Scale Experimental Machine (SSEM), was the world's first stored-program computer. It was built at the Victoria University of Manchester, England, by Frederic C. Williams, Tom Kilburn and Geoff Tootill, and ran its first program on 21 June 1948.