______ establishes information about when, why and by whom changes are made in…

CONCEPT

Software change governance uses several related mechanisms. A management discipline controls configuration items and baselines; a control process authorizes proposed changes; a versioning tool stores revisions; and a trace record preserves evidence about actions that occurred.

The deciding distinction is between managing or approving change and recording the provenance of completed actions.

APPLICATION

The blank asks for the mechanism that establishes when a change occurred, why it was made, and who made it. Those are provenance and accountability details, so the described mechanism is an audit trail.

CONTRAST

• Software Configuration Management is the broader discipline that coordinates configuration identification, control, status accounting, and auditing.

• Change Control evaluates and authorizes proposed modifications.

• Version Control manages successive versions of files and other artifacts.

• An Audit Trail preserves a chronological, attributable record of actions and changes.

CROSS-CHECK

Substituting the terms into the sentence confirms the distinction: approval and version storage do not by themselves supply the full when–why–who record, whereas an audit trail is maintained for exactly that traceability purpose.

Therefore, the answer is An Audit Trail.