Which open-source tools can be integrated with SAP BTP for enhanced observability?

In observability:

Prometheus (A):

Used for metrics scraping and monitoring, and commonly integrated with BTP systems (especially Kyma).

Logstash (C):

Part of the Elastic Stack, used for log forwarding and transformation, can be integrated with BTP for centralized logging pipelines.

Incorrect options:

B – Terraform: An IaC tool, not an observability tool.

D – Jenkins: A CI/CD tool, not for observability.