A customer is connecting Sales Cloud with Marketing Cloud. The connection was successful, however, the team is unable to view or sync Sales Cloud objects in Contact Builder. How should a consultant begin troubleshooting the connection?

A. Create and send an email in Email Studio to test the connection and validate tracking.

B. Validate Marketing Cloud and Sales Cloud users have access to the business unit.

C. Create new Marketing Cloud and Sales Cloud users and perform a new installation.

D. Validate Marketing Cloud and Sales Cloud permissions for the connecting users