The correct answer is B. EDSAC.
EDSAC (Electronic Delay Storage Automatic Computer) was the first stored-program electronic computer, built at the University of Cambridge Mathematical Laboratory in England. It was designed by Maurice Wilkes and his team, and was operational from 1949 to 1958.
EDSAC was a significant advance over earlier computers, such as the ENIAC and EDVAC, which were not stored-program computers. EDSAC was the first computer to be able to store its program in memory, which made it much faster and more versatile than earlier computers.
EDSAC was used for a variety of scientific and engineering calculations, including the calculation of the trajectory of the first British satellite, Ariel 1. It was also used to develop early computer games, such as Nim and Tic-Tac-Toe.
EDSAC was a pioneering computer that helped to lay the foundations for the development of modern computers.
A. EDVAC (Electronic Discrete Variable Automatic Computer) was the second stored-program electronic computer, built at the University of Pennsylvania in the United States. It was designed by John von Neumann and his team, and was operational from 1951 to 1955.
B. EDSAC (Electronic Delay Storage Automatic Computer) was the first stored-program electronic computer, built at the University of Cambridge Mathematical Laboratory in England. It was designed by Maurice Wilkes and his team, and was operational from 1949 to 1958.
C. UNIVAC (Universal Automatic Computer) was the first commercial electronic computer, built by Remington Rand in the United States. It was operational from 1951 to 1961.
D. MARK-I was an electromechanical computer built by Howard Aiken at Harvard University in the United States. It was operational from 1944 to 1959.
E. None of the above.