Comprehensive and Detailed Explanation From Exact Extract:
SRE defines effective monitoring as comprehensive observability across all layers of a system, including latency, traffic, errors, saturation, dependencies, and infrastructure. The SRE Book states: “Monitoring must offer insight across all system components, enabling teams to rapidly detect and diagnose issues.” (SRE Book – Monitoring Distributed Systems). Observability instrumentation (logs, metrics, traces) provides the necessary depth for reliable digital experience monitoring.
Option B captures this exactly: broad observability across all components and layers.
Option A rejects modern observability practices—contradicting SRE guidance.
Option C is too narrow (network-only).
Option D focuses only on advanced technologies, not comprehensive coverage.
Thus, B is the best answer.
[References:, Site Reliability Engineering, Chapter: “Monitoring Distributed Systems.”, The Site Reliability Workbook, Observability and Monitoring chapters., , ]
