Answer 2
Analysis. Answer option C is correct.
XmlReadMode specifies how to read XML data and the related schema to a DataSet. Following is the syntax for using the ReadXml(String, XmlReadMode) method of the DataSet class:
datasetobjectname.ReadXml(filename, mode)
where, datasetobjectname specifies the name of the DataSet object, filename specifies the file name, including the path, from which data is to be read, and mode specifies an XmlReadMode value. The ReadXml method always returns XmlReadMode that is used to read data. Following are the values that can be used for XmlReadMode:
XmlReadMode value Description
DiffGram It is used to read a DiffGram, applying changes from the DiffGram to a DataSet object.
ReadSchema It is used to read an inline schema and load data.
IgnoreSchema It specifies that an inline schema is to be ignored and data is to be read into an existing DataSet object. The data is discarded if it does not match the existing schema.
InferSchema It is used to ignore an inline schema, infer schema from data, and load the data. If a DataSet object already contains a schema, the schema is extended by adding new tables or columns to the tables.
Auto It is the default XmlReadMode value. It works as the DiffGram, ReadSchema, or InferSchema value, whichever is appropriate for a particular situation.
Fragment It is used to read XML documents.
== What is DataSet==
DataSet is a memory-resident representation of data. It represents related tables, constraints, and relationships among the tables. DataSet reads and writes data and schema as XML documents.