Comprehensive and Detailed Explanation From Exact Extract:

Swarming is described in modern SRE incident management as a collaborative, multi-expert response model. Instead of linear escalation, SRE uses: “a rapid collaboration of the right experts at the same time to resolve incidents quickly.” (SRE Workbook – Effective Incident Response). Swarming pulls specialists together immediately, allowing them to jointly triage and work on issues, improving time-to-resolution and reducing handoff delays.

Option D captures this: multiple specialist teams coming together simultaneously to determine ownership and action.

Option A describes traditional tiered escalation, which SRE avoids.

Option B represents a reactive queue model, not swarming.

Option C focuses on monitoring progress, not active collaborative response.

Thus, D is correct.