Which method will result in unique names per VM when scaling out a Service in...

The correct method to result in unique names per VM when scaling out a Service in a Calm Blueprint is to use the macro variable @@{calm_array_index}@@ in the Service VM Name field (Option B). This variable will append a unique index number to each VM name based on the scale-out count. For example, if the Service VM Name is MyAppVM-@@{calm_array_index}@@ and the scale-out count is 3, the resulting VM names will be MyAppVM-0, MyAppVM-1, and MyAppVM-2. Option A is incorrect because the tag in the sysprep file will only affect the hostname of the guest OS, not the VM name in the cloud provider. Option C is incorrect because calling an external Python eScript to register the VM name in DNS will not change the VM name in the cloud provider either. Option D is incorrect because setting the VM Name field to allow user edits at launch will require manual input from the user for each VM, which is not scalable or automated.

References: The information can be verified from Nutanix official training and certification documents available at Nutanix Training & Certification. You can also check out the Nutanix Certified Professional - Multicloud Automation (NCP-MCA) 6.5 Exam guide for more details on the exam objectives and format. Additionally, you can watch the Nutanix Calm - Multicloud Automation playlist on YouTube for some video tutorials on Nutanix Calm features and functionalities.