how to specify one property to come under a node as subnode in xml using attributes

Question

public class abc
    {
        public string b;
        public string c;
    }

<a>
  <b></b>
  <c></c>
</a>

and can we explicitly specify "a"

Answer 1

You can't specify "a". "a" doesn't belong to class "abc" - it belongs to the class that c ontains an instance of class "abc":

public class def
{
    [XmlElement("a")]
    public abc abc {get;set;}
}