Step 1: Software Configuration Management (SCM) tracks and controls changes to work products across the project.
Step 2: Core SCM tasks are identifying configuration items, controlling changes, tracking versions, and auditing. The heart of this is keeping and managing versions of files.
Step 3: Version Control stores every revision, allows rollback, and merges parallel work. It is a direct part of SCM.
Step 4: Testing, design, and maintenance are separate software activities, not the defining component of configuration management.
So the answer is option C.