To answer this question, the user needs to know about DD statements and their purpose. DD (Dataset Definition) statements are used to define and allocate datasets in JCL (Job Control Language) for use by a job step.
The correct answer is option B.
Explanation:
The DD statement used to supply the name of a dataset is the Dsname parameter. This parameter specifies the name of the dataset being allocated or accessed by a job step.
Option A (Name) is not a valid parameter in a DD statement.
Option C (Label) is used to specify a label for a dataset.
Option D (File) is also not a valid parameter in a DD statement.
Option E (None of the above) is incorrect because option B (Dsname) is the correct answer.