You create an application by using the Microsoft .NET Framework 3.5 and Microsoft ADO.NET.

The application uses the following LINQ query.

var query = from o in orderLinesQuery
where (string)o["CarrierTrackingNumber"] == "AEB6-4356-80"
select new
{
SalesOrderID = o.Field<int>("SalesOrderID"),
OrderDate = o.Field<DateTime>("OrderDate")
};

The CarrierTrackingNumber field in the DataRow is nullable. You need to ensure that an exception does not occur if the CarrierTrackingNumber field has a null value.

Which code segment should you use?

A.
var query = from o in orderLinesQuery
where !o.IsNull("CarrierTrackingNumber") &&
(string)o["CarrierTrackingNumber"] == "AEB6-4356-80"
select new
{
SalesOrderID = o.Field<int>("SalesOrderID"),
OrderDate = o.Field<DateTime>("OrderDate")
};

B.
var query = from o in orderLinesQuery
where o.IsNull("CarrierTrackingNumber") &&
(string)o["CarrierTrackingNumber"] == "AEB6-4356-80"
select new
{
SalesOrderID = o.Field<int>("SalesOrderID"),
OrderDate = o.Field<DateTime>("OrderDate")
};

C.
var query = from o in orderLinesQuery
where o.Field<string>("CarrierTrackingNumber") == "AEB6-4356-80" select new
{
SalesOrderID = o.Field<int>("SalesOrderID"),
OrderDate = o.Field<DateTime>("OrderDate")
};

D.
var query = from o in orderLinesQuery
where (string)o["CarrierTrackingNumber"] == DbNull.Value &&
(string)o["CarrierTrackingNumber"] == "AEB6-4356-80"
select new
{
SalesOrderID = o.Field<int>("SalesOrderID"),
OrderDate = o.Field<DateTime>("OrderDate")
};