The correct answer is C. ENIAC.
The ENIAC (Electronic Numerical Integrator and Computer) was the first general-purpose electronic computer. It was built at the University of Pennsylvania’s Moore School of Electrical Engineering and was completed in 1946. The ENIAC was used to calculate ballistics tables for the U.S. Army during World War II. It was also used for a variety of other purposes, including weather forecasting, nuclear research, and aircraft design.
The ENIAC was a massive machine, weighing 30 tons and occupying 1,800 square feet of floor space. It contained 17,468 vacuum tubes, 70,000 resistors, 10,000 capacitors, and 6,000 switches. It was programmed by plugging and unplugging cables and setting switches.
The ENIAC was a major breakthrough in computer technology. It was the first computer to be able to perform complex calculations automatically. It also paved the way for the development of smaller, faster, and more powerful computers.
The other options are incorrect for the following reasons:
- The IBM 405 was a punch-card tabulator that was introduced in 1924. It was not a general-purpose computer.
- The Zuse Z3 was a mechanical computer that was developed in Germany in the 1930s. It was not an electronic computer.
- The CSIRAC was an electronic computer that was developed in Australia in the 1940s. It was not the first general-purpose electronic computer.