Explanation/Reference:
Incorrect answers:
A: Cloud computing implies diverse, heterogeneous multi-tenancy. This increases the operational risk security issues. The technology to accomplish this is not just OS virtualization. It can involve everything from lower levels OS partitioning to application server co-tenancy. Importantly Cloud multi-tenancy endeavors to make each tenant feel as though they are the sole user, with no visibility into other execution and user environments B: In a nutshell Cloud is a style of computing in which dynamically scalable and rapidly deployable IT resources are provided as a service over a network (typically the internet).
One of the key differentiators of cloud over "hosting" is the ability to expand and contract resources on- demand (i.e. "dynamically scalable"). This characteristic is also referred to as "elasticity" and is a key capability of Cloud computing that traditional "hosting" does not provide.
C: The following three key benefits address improving the economics of businesses' use of IT:
* aligning costs with utilization
* reducing the need for in-house IT staff (and related costs)
* replacing large up-front financial outlays with streaming payments
Note: In summary the expectations for Cloud include:
* reduced cost
* higher availability
* unconstrained growth of IT capabilities
* removal of barriers to technology intensive business initiatives
* increased speed to market
* access to more IT options
Reference: Oracle Reference Architecture, Cloud Foundation Architecture, Release 3.0