You want to make API calls against other OCI services from your instance without configuring...

Detailed Answer in Step-by-Step Solution:

Objective: Enable credential-less API calls from an instance.

Understand Resource Principal: Allows instances to authenticate via IAM without user creds.

Evaluate Options:

A: Dynamic group + policy—Correct; groups instance, grants access.

B: Dynamic group only—Incomplete; needs policy.

C: User group—Irrelevant for instances.

D: No config—False; setup required.

Reasoning: A sets up resource principal fully—group and perms.

Conclusion: A is correct.

OCI documentation states: “To make API calls without credentials, create a dynamic group including the instance and add a policy (A) granting access to OCI services—enables resource principal.” B lacks policy, C is user-based, D is false—only A completes the process per OCI’s IAM setup.

Oracle Cloud Infrastructure IAM Documentation, "Resource Principal Configuration".