Integrated circuits were the defining electronic component of which generation of computers?

The correct answer is B, the third generation. The integrated circuit packs many transistors and other components onto a single silicon chip, and computers built on it were far smaller, cheaper and more reliable than their predecessors. The third generation also introduced the keyboard and monitor in place of punched cards and the operating system that allowed several programs to share the machine, with the IBM System 360 as the standard example.

Option A, the second generation, is the age of the individual transistor, not of chips carrying many of them. Option C, the fourth generation, is defined by the microprocessor and very large scale integration, where an entire processor sits on one chip. Option D, the fifth generation, is described in terms of ultra large scale integration, parallel processing and artificial intelligence rather than a single new component. The trap is that a microprocessor is itself an integrated circuit, so match the exact word the question uses.