You want to add a new auditor to a Google Cloud Platform project. The auditor should be allowed to read, but not modify, all project items. How should you configure the auditor`s permissions? 

Answer options:

A. Create a custom role with view-only project permissions. Add the user`s account to the custom role.
B. Create a custom role with view-only service permissions. Add the user`s account to the custom role.
C. Select the built-in IAM project Viewer role. Add the user`s account to this role.
D. Select the built-in IAM service Viewer role. Add the user`s account to this role.

C

Reference: https://cloud.google.com/resource-manager/docs/access-control-proj