Platform Services provide shared foundations that other Zero Trust Exchange services consume. These include identity, policy framework, TLS decryption, device posture, logging, APIs, and other common capabilities that support ZIA, ZPA, ZDX, and related services. Option D (Platform Services) is correct because Platform Services are the common dependency layer.

Why the other options are incorrect:

A. Access Control Services: Access Control Services enforce user and application access decisions. They sit on top of the shared platform foundations rather than providing those foundations themselves.

B. Digital Experience Monitoring: Digital Experience Monitoring measures performance and user experience. It relies on the platform services layer for identity, policy, and telemetry foundations.

C. Cyber Security Services: Cyber Security Services inspect and block threats. They are consumers of the common platform layer, not the base layer that other services depend on.