Computers are machines that help us in many ways, but they cannot think or do things on their own. Humans have to provide them with information and tell them what to do with it. Computers cannot come up with any new information, but they can save time by making work processes more efficient. For example, information and office files can be stored in a computer's "memory." Computers can trace information from a particular file within a few seconds. It would take a clerk days or even weeks to go through every file if no computers were used.
The first computers were huge and costly. They filled up almost the whole floor of large offices. Later, because of the usefulness and demand for computers in business, scientists soon found ways to produce cheaper and smaller computers. They invented chips which made it possible to store more information in less space.
Today, computers are not only cheaper, but also more compact. They can be placed on top of an ordinary writing table. They can even be carried from place to place easily. Computers are not only used in offices by companies, but they are also used at home.
According to the passage, computers:
a) can trace a particular file in a few seconds.
b) help us in many ways by coming up with new information.
c) are more useful in an office setting.
d) are now more costly and compact.