What could be the reason for this exception?

You work as a Web Developer in PassGuide.com. The company uses Microsoft .NET Framework
4 as its application development platform. You write a query that uses Include() method. However,
an ArgumentException is thrown by this method. What could be the reason for this exception?

A.
The object is null.

B.
The path is null.

C.
The path is empty.

D.
The object is in Added state.

Explanation: