To answer this question, you need to understand the advantages of GDG (Generation Data Group).
Let's go through each option to understand why it is correct or incorrect:
Option A) It will maintain all generation of data sets - This option is correct. GDG allows you to maintain multiple generations of data sets, which means you can keep track of different versions or iterations of the same data set. Each generation is assigned a unique generation number, and you can access or refer to any generation using this number.
Option B) It will catalog older generation files - This option is incorrect. GDG does not specifically catalog older generations of files. However, you can still access older generations using their generation numbers.
Option C) No need to change the JCL every time when we submit - This option is correct. GDG simplifies the process of accessing different generations of data sets by providing a common name and a generation number. With GDG, you don't need to modify the Job Control Language (JCL) every time you want to access a different generation. You can simply reference the GDG base name and the desired generation number in your JCL, making it easier to manage and maintain.
Option D) None of these - This option is incorrect. As explained above, options A and C are correct, making the correct answer A,C.
The correct answer is A,C. These options highlight the advantages of GDG, including maintaining all generations of data sets and eliminating the need to change the JCL every time you submit.