A microservice architecture uses 20 different secrets. Which Key Vault design approach reduces operational overhead?

1. A One Key Vault per microservice (20 vaults)
2. B One shared vault for all microservices with RBAC controlling access per service
3. ✓ C One vault per environment (dev/staging/prod) (correct answer)
4. D Store secrets in Azure Table Storage with encryption

Shortcut: One vault per environment (dev, staging, prod) balances operational simplicity with security isolation. RBAC within each vault controls which services/identities access which secrets. One per microservice creates excessive management overhead.