To answer this question, we need to understand the parameters and keywords used in DD statements.
DD statements are used in JCL (Job Control Language) to define and describe the datasets that a job will use. These statements provide information such as the dataset name (Dsname), allocation parameters (SPACE), disposition (DISP), and organization (DCB).
Let's go through each option to understand which parameters are required:
Option A) Dsname, SPACE, UNIT - This option is incorrect because it does not include the required DISP and DCB parameters.
Option B) Dsname, SPACE, RECFM - This option is incorrect because it also does not include the DISP and DCB parameters.
Option C) Dsname, DISP, DCB, SPACE - This option is incorrect because it includes all the required parameters.
Option D) All parameters & Keywords are optional - This option is correct because all parameters and keywords in a DD statement are optional. However, at least one parameter is required in order to define a dataset.
Therefore, the correct answer is option D) All parameters & Keywords are optional. This option is correct because while all parameters are optional, at least one parameter is required to define a dataset.