Which of the Following Differentiates Grid Computing from Cloud Computing

Which of the following differentiates grid computing from cloud computing?

A) Grid computing uses a large number of computers.
B) Grid computing is a natural evolution of the widespread adoption of virtualization and utility computing.
C) Grid computing is applied to a single large problem.
D) Grid computing involves over-the-Internet provision of dynamically scalable and often virtualized resources.
E) Grid computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources.