Why if in sql server i have a xml column, in .net with sqldatareader/sqldataadapter i have a string?

See the example in pic, cast c1 in xml, but .Net get string.

I tried also with xml column, always string.

this my code

SqlCommand sc = new SqlCommand("select *,convert(xml,c1)c6 from tempdb..t1", conn);

DataTable dt = new DataTable();
new SqlDataAdapter(sc).Fill(dt);