How to solve “Must be MarshalByRefObject” in a good but multiple-inheritance amputated language like C#?

Question

How to solve \"Must be MarshalByRefObject\" in a good but multiple-inheritance amputated language like C#?

The problem is very simple, in several cases you just have

Answer 1

"So, what do you do if you've already inherited from some other class (your domain model requirements)?"

Can you create a base class for the piece of your domain model that requires inheritance from MarshalByRefObject?