Alternatively referred to as PC DOS, IBM DOS is a text-based operating system similar to Microsoft’s DOS, but only sold by IBM. DOS is a single-user, single-tasking operating system with basic kernel functions that are non-reentrant: only one program at a time can use them and DOS itself has no functionality to allow more than one program to execute at a time.

Correct Option: A

Alternatively referred to as PC DOS, IBM DOS is a text-based operating system similar to Microsoft’s DOS, but only sold by IBM. DOS is a single-user, single-tasking operating system with basic kernel functions that are non-reentrant: only one program at a time can use them and DOS itself has no functionality to allow more than one program to execute at a time.

UNIX is a popular multi-user, multitasking operating system developed at Bell Labs in the early 1970s. Created by just a handful of programmers, UNIX was designed to be a small, flexible system used exclusively by programmers. It was designed to be portable, multi-tasking and multi-user in a timesharing configuration.

Correct Option: A

UNIX is a popular multi-user, multitasking operating system developed at Bell Labs in the early 1970s. Created by just a handful of programmers, UNIX was designed to be a small, flexible system used exclusively by programmers. It was designed to be portable, multi-tasking and multi-user in a timesharing configuration.

Secondary storage, sometimes called auxiliary storage, is all data storage that is not currently in a computer's primary storage or memory. In a personal computer, secondary storage typically consists of storage on the hard disk and on any removable media, if present, such as a CD or DVD, flash memory, floppy disks, magnetic tape, paper tape, punched cards, standalone RAM disks, and Iomega Zip drives.

Correct Option: B

Secondary storage, sometimes called auxiliary storage, is all data storage that is not currently in a computer's primary storage or memory. In a personal computer, secondary storage typically consists of storage on the hard disk and on any removable media, if present, such as a CD or DVD, flash memory, floppy disks, magnetic tape, paper tape, punched cards, standalone RAM disks, and Iomega Zip drives.

Electronic mail, most commonly referred to as email, is a method of exchanging digital messages from an author to one or more recipients. Normally, there could be three types of recipients: the target recipient; a carbon copy (Cc) recipients; and blind carbon copy (Bcc) recipients.

Correct Option: A

Electronic mail, most commonly referred to as email, is a method of exchanging digital messages from an author to one or more recipients. Normally, there could be three types of recipients: the target recipient; a carbon copy (Cc) recipients; and blind carbon copy (Bcc) recipients.

A supercomputer is used for processing of information on quantum mechanics, large scale weather forecasting, molecular studies, polymer research, to solve mathematical problems, wind tunnel research, and chemical composition. Meteorologists use them to do research on the climate and global warming. It was first created in 1960.

Correct Option: C

A supercomputer is used for processing of information on quantum mechanics, large scale weather forecasting, molecular studies, polymer research, to solve mathematical problems, wind tunnel research, and chemical composition. Meteorologists use them to do research on the climate and global warming. It was first created in 1960.