The correct answer is D. All of the mentioned.
Different types of cloud computing service models provide different levels of security services. For example, Infrastructure as a Service (IaaS) providers offer the least amount of security, while Platform as a Service (PaaS) and Software as a Service (SaaS) providers offer more security.
Adapting your on-premises systems to a cloud model requires that you determine what security mechanisms are required. This includes identifying the data that needs to be protected, the level of protection required, and the best way to implement the security mechanisms.
Data should be transferred and stored in an encrypted format for security purpose. This helps to protect the data from unauthorized access and use.
In addition to the above, it is important to have a strong security policy in place when using cloud computing. This policy should address issues such as data encryption, access control, and incident response.