According to Pega best practices, which phase can you implement as a child case?

The business process for an automobile insurance claim consists of the following phases:

* Submission: The customer contacts a customer service representative (CSR) to file the claim.

* Review: An adjuster reviews the claim, assesses the damages to each vehicle, and provides an estimate of the cost of repairs.

* Repair: A third patty performs the repairs on each vehicle, communicating with the adjuster and customer as necessary.

* Verification: After each vehicle repair, the adjuster closes the claim.

According to Pega best practices, which phase can you implement as a child case?
A . Review
B . Verification
C Repair
C . Submission