Which of the following is a lightweight object used for read-only access to data?

A.
DataSource

B.
DataReader

C.
SqlDataReader

D.
REST-compliant Web services

Explanation:
The W3C also identifies two major classes of Web services, which are as follows:
1.The REST-compliant Web services in which the basic use of the service is to manipulate XML
representations of the Web resources through a uniform set of “stateless” operations.
2.The Arbitrary Web services in which the service may possibly represent an arbitrary set of
operations.
Answer A is incorrect. Windows Service is a long-running executable that performs specific
functions and does not require user intervention.
Answer C is incorrect. A console application is a computer program designed to be used via a textonly computer interface, such as a text terminal, or the command line interface of some operating
systems.
Answer B is incorrect. Global.asax is an optional file that contains code for responding to global
events that occur in a Web application. There can be only one Global.asax file for an application. This
file resides in the root directory of an ASP.NET application. External users cannot download or view
the code written within the Global.asax file.