Explanation:

Compatibility, in the context of computers and software, refers to the ability of different components or programs to work together without conflict or issues. Option (c) 'The software being able to run on the computer' is the most fundamental definition of compatibility. If software is compatible with a computer, it means it can be installed and executed on that specific hardware and operating system environment. Option (a) 'The software doing the right job for the user' describes the functionality or utility of the software, not its compatibility. Option (b) 'It being versatile enough to handle the job' describes the flexibility of the software, not its basic ability to operate on a system. Option (d) 'Software running with other previously installed software' describes interoperability between different software applications, which is a specific aspect of compatibility, but the core meaning of software compatibility with a computer system is its ability to execute on that system.