Declaring an object which can be of any Type in c#

Question

I am looking for an implementation similar to the type 'id' in objective c which can be of any type during runtime.Is it possible to do that in c#?

let me explain my requirement

id abc;// a common type which can hold any object during runtime
if(cond1)
{
 Option1 opt1 = new Option1();//opt1 is an object of user defined class Option1
 abc = opt1;
}
else if(cond2)
{
 Option2 opt2 = new Option2();
 abc = opt2;
}
...

How can I do the same in c# ? Thanks, Nikil.

Answer 1

Declare an object or use the dynamic keyword as others say, or if you know an interface or base class that all your possible objects derive from, use that type:

IOption abc;

Answer 2

dynamic types are exactly for this purpose. Their "type" is dynamic(which obviously means at run-time).

I don't know about objective-C but it seems like id = dynamic.

Essentially a dynamic type is treated as a "typeless" object. There is no intellisense and no type checking done at compile time.