You use Microsoft .NET Framework 4.0 to develop an application.
You write the following code to update data in a Microsoft SQL Server 2008 database.
(Line numbers are included for reference only.)

01 private void ExecuteUpdate(SqlCommand cmd, string connString, string updateStmt)
02 {
03 …
04 }

You need to ensure that the update statement executes and that the application avoids connection leaks.
Which code segment should you insert at line 03?

A.
SqlConnection conn = new SqlConnection(connString);
conn.Open();
cmd.Connection = conn;
cmd.CommandText = updateStmt;
cmd.ExecuteNonQuery();
cmd.Connection.Close() ;

B.
using (SqlConnection conn = new SqlConnection(connString))
{
cmd.Connection = conn;
cmd.CommandText = updateStmt;
cmd.ExecuteNonQuery();
cmd.Connection.Close();
}

C.
using (SqlConnection conn = new SqlConnection(connString))
{
conn.Open() ;
cmd.Connection = conn;
cmd.CommandText = updateStmt;
cmd.ExecuteNonQuery() ;
}

D.
SqlConnection conn = new SqlConnection(connString);
conn.Open();
cmd.Connection = conn;
cmd.CommandText = updateStmt;
cmd.ExecuteNonQuery();

Explanation:
http://www.w3enterprises.com/articles/using.aspx
http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.aspx