You are working on a sensitive project involving private user data. You have set up a project on Google Cloud Platform to house your work internally. An external consultant is going to assist with coding a complex transformation in a Google Cloud Dataflow pipeline for your project. How should you maintain users' privacy?

A. Grant the consultant the Viewer role on the project. B. Grant the consultant the Cloud Dataflow Developer role on the project. C. Create a service account and allow the consultant to log on with it. D. Create an anonymized sample of the data for the consultant to work with in a different project.