Is this the reason         he gave us for the delay of the project?[ ]

A. how

B. what

C. why

D. that

Microsoft’s COM is a software architecture that allows applications to be built from binary software components. COM is the underlying (1) that forms the foundation for higher-level software services, like those provided by OLE. COM defines a binary standard for function calling between components, a way for components to dynamically discover the interfaces implemented by other components, and a mechanism to identify components and their interfaces uniquely.

OLE is a compound (2) standard developed by Microsoft. OLE makes it possible to create (3) with one application and link or embed them in a second application. Embedded objects retain their original format and (4) to the application that created them. Support for OLE is built into the Windows and MacOS Operating Systems. A (5) compound document standard developed mainly by Apple and IBM is called OpenDoc.

5（）

A．connecting

B．contained

C．completing

D．competing