Correct Answer : Option (B) - 1959 – 1964
The period 1953-1964 is generally taken to be the period of second generation computers. Sometimes, 1946-1958 is supposed to be the period of first generation computers. By 1948, the invention of the transistor greatly changed the computer's development. The transistor replaced the large, cumbersome vacuum tube in televisions, radios and computers. As a result, the size of electronic machinery has been shrinking ever since. From 1955 onwards transistors replaced vacuum tubes in computer designs, giving rise to the "second generation" of computers. A second generation computer, the IBM 1401, captured about one third of the world market. IBM installed more than ten thousand 1401s between 1960 and 1964.