Which of the following are correct ports for the specified components in the OpenTelemetry Collector?

The correct answer is D. gRPC (4317), SignalFx (9080), Fluentd (8006).

According to the web search results, these are the default ports for the corresponding components in the OpenTelemetry Collector. You can verify this by looking at the table of exposed ports and endpoints in the first result1. You can also see the agent and gateway configuration files in the same result for more details.

1: https://docs.splunk.com/observability/gdi/opentelemetry/exposed-endpoints.html