Write a Social Proof Block

Write a social proof block for a landing page section:

Product / offer: [PRODUCT]
Audience: [ICP]
Proof available: [METRICS / LOGOS / QUOTES / CASE STUDIES]
Section goal: [TRUST / CONVERSION]
Tone: [TONE]
Claims that need a source: [LIST OR NONE]

Requirements:
1. Propose 3 layout options (logo row, quote stack, metric + quote).
2. Write headline options and supporting lines that only use given proof.
3. Mark any claim that needs a source before publish.
4. Include alt text guidance for logo images.
5. Add a fallback version if only one proof type is available.

Deliverables:
1. Three social proof block variants with copy.
2. A recommended variant with a one-sentence rationale.
3. A source checklist for legal or brand review.