Final answer:
The correct statement is that an output control data set contains format information and is created with the CNTLOUT= option in PROC FORMAT in SAS.
Step-by-step explanation:
The statement that best describes the purpose of the output control data set is: d. The output control data set contains information that describes formats. It is the data set that is created with the CNTLOUT= option in the PROC FORMAT statement.
In SAS, the PROC FORMAT step is used to define custom formats for data values. When you use the CNTLOUT= option, SAS creates an output control data set that captures the format definitions you've specified within the PROC FORMAT step. This allows you to save these format definitions in a SAS data set, and you can later use this data set to recreate the same formats without needing to redefine them manually in your code.