How can this be confirmed?

Northern Trail Outfitters (NTO) has over 20,000 Accounts and 75,000 Contacts. NTO wants to ensure the customer data is accurate and that the customers are still currently at their respective companies.

How can this be confirmed?
A . Use a data enrichment tool to verify account and contact data is up-to-date.
B . Create a workflow rule to mass email the contacts and capture any email bounces.
C . Create a workflow rule for the account and contact owner to confirm contact data.
D . Use a data cleansing tool and the Stay-in-Touch feature of Salesforce to email contacts.

Answer: D