The correct answer is B. 4004.
The Intel 4004 was the first microprocessor, a computer processor on a single integrated circuit. It was developed by Federico Faggin, Marcian Hoff, Stanley Mazor, and Masatoshi Shima at Intel, and first released in November 1971. The 4004 was designed for a Japanese calculator company, Busicom, to replace a custom-designed set of 12 chips. It was a revolutionary product that led to the development of the modern microprocessor industry.
The 4004 was a 4-bit microprocessor with 2300 transistors. It had a clock speed of 108 kHz and could perform 60,000 operations per second. It had 40 instructions and 16 registers. The 4004 was used in a variety of applications, including calculators, cash registers, and video games.
The 4004 was followed by the 8008 in 1972, the 8080 in 1974, and the 8086 in 1978. These processors were all based on the 4004 architecture, but they were more powerful and had more features. The 8086 was the first 16-bit microprocessor, and it was the basis for the x86 architecture that is still used in most personal computers today.
The Intel 4004 was a revolutionary product that led to the development of the modern microprocessor industry. It was the first microprocessor, and it was followed by a series of more powerful and capable processors that are still used in many applications today.