Which Azure service should a security analyst use to store application secrets and enforce access policies?

Azure Key Vault is the correct choice because it is specifically designed to securely store and manage sensitive information like API keys, passwords, certificates, and other secrets. It allows for centralized management of application secrets, with robust access policies and auditing capabilities. Azure Monitor is for collecting, analyzing, and acting on telemetry data from your Azure and on-premises environments. Azure Security Center provides unified security management and advanced threat protection across hybrid cloud workloads. Azure Bastion is a fully managed PaaS service that provides secure and seamless RDP/SSH connectivity to your virtual machines directly from the Azure portal over SSL.