The invention of the transistor, or semiconductor, was one of the most important developments leading to the personal computer revolution. What company invented the transistor in 1947?

International Business Machines
MITS
Xerox
Bell Laboratories

The correct answer is D. Bell Laboratories.

Bell Laboratories is an American research and development company with facilities in the United States and around the world. It was founded in 1925 by AT&T to conduct research in support of its manufacturing and communications operations. Bell Labs has been responsible for many important inventions, including the transistor, the laser, the Unix operating system, and the C programming language.

International Business Machines (IBM) is an American multinational technology company headquartered in Armonk, New York, with operations in over 170 countries. The company began in 1911 as the Computing-Tabulating-Recording Company (CTR) and was renamed “International Business Machines” in 1924. IBM is one of the world’s largest employers, with more than 352,600 employees in 2020. The company is a major player in the information technology industry, providing hardware, software, and services to businesses and governments around the world.

Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts. Established in 1861 in response to the increasing industrialization of the United States, MIT adopted a European polytechnic university model and stressed laboratory instruction in applied science and engineering. The institute is often ranked among the world’s most prestigious universities.

Xerox Corporation is an American multinational information technology, document management, and consulting company headquartered in Norwalk, Connecticut. It was founded in 1906 as the Haloid Photographic Company and renamed Xerox in 1961. The company is best known for its xerography technology, which is used in photocopiers and printers. Xerox also provides document management software, services, and solutions to businesses and governments around the world.