Which of the following is the MOST significant risk to business continuity when using an external cloud service provider?

A.
Unauthorized access to customer data

B.
Vendor being purchased

C.
Virtual server failure

D.
Vendor going out of business

Explanation:
If your application stores and retrieves very sensitive data, you might not be able to maintain it in the cloud.
Similarly, compliance requirements could also limit your choices.
http://cloudacademy.com/blog/cloud-migration-benefits-risks/