Explanation:

Why Option A is Best:
Case History automatically tracks timestamps and user actions (e.g., when an item was started, paused, resumed, or completed) on a case.

Visibility for All Agents: Since multiple agents work on the same case, the Case History related list provides a shared audit trail of actions.

No Configuration Needed: Enabled by default; no setup required beyond adding the related list to the page layout.

Why Other Options Are Not Ideal:
B. Actions & Recommendations Component – Shows Einstein Next Best Action suggestions, not historical activity tracking.
C. Activity Analytics Tab – Provides aggregate metrics (e.g., time spent), not granular timestamps of actions.

Reference:
Case History Tracking:
View Case History
Track Field Changes
Conclusion:
For transparency on multi-agent case work, Option A (Case History) is the only out-of-the-box solution. ✅

Implementation Tip:
Add the Case History related list to the Case page layout if not already visible.
Use Activities (Tasks/Events) to log manual work timestamps if needed.