Consider a new version of an operating system. While deciding the scope of what needs to be tested in that version, which of these features would be essential to test? 1. The OS introduces support for...

Consider a new version of an operating system. While deciding the scope of what needs to be tested in that version, which of these features would be essential to test? 1. The OS introduces support for a new network protocol which is becoming a de facto standard 2. The OS has been modified to work in an embedded system on a manned flight to Mars 3. The OS feature for support for long file names has been stable and working for the past five versions and has not undergone any major change 4. The caching part of the file system of the OS has often given performance problems and every slight change seems to upset the apple cart 5. The features of OS are expected works on different chips and in a network, different machines may be running on different chips