Final answer:
The SAS procedure to manage a SAS catalog is PROC CATALOG. It helps in maintaining and manipulating catalogs which are files storing various information used within SAS, the correct option is C).
Step-by-step explanation:
The procedure that enables you to manage a SAS catalog is PROC CATALOG. This procedure provides tools for maintaining and manipulating catalogs and catalog entries in SAS.
Catalogs are specialized SAS files that store many types of information, such as formats, informats, macros, and compiled PROC REPORT definitions. With PROC CATALOG, you can copy, delete, rename, and change attributes of catalog entries, as well as create listings of catalog contents.
Other options mentioned in the question such as PROC COPY, PROC CATMOD, and PROC CONTENTS serve different purposes. PROC COPY is used to copy SAS files, PROC CONTENTS displays information about a SAS dataset, and PROC CATMOD (which is not a standard SAS procedure) does not exist.