A. ट्रांजिस्टर
B. वैक्यूम ट्यूब और वाल्व
C. एकीकृत सर्किट
D. इनमे से कोई भी नहीं

Solution

B. Vacuum Tubes and Valves

Explanation

Transistors were used for second generation computers and integrated circuits in third generation. First generation computers used vacuum tubes and valves as their main electronic component. Vacuum Tubes were invented by Lee DeForest in 1908.