Your customer is running a set of compute instances inside a private subnet to manage their workloads on Oracle Cloud Infrastructure (OCI) tenancy. You have set up auto scaling feature to provide consistent performance to their end users during period of high demand. Which step should be met for auto scaling to work? (Choose the best answer.) 

Answer options:

A. OS Management Service agent (osms) must be installed on the instances.
B. Audit logs for the instances should be enabled.
C. Service gateway should be setup to allow instances to send metrics to monitoring service.
D. Monitoring for the instances should not be enabled.

B

Reference: https://docs.oracle.com/en-us/iaas/Content/Compute/Tasks/autoscalinginstancepools.htm