You need to call an unmanaged function from your managed code by using platform invoke services. What should you do?

You need to call an unmanaged function from your managed code by using platform invoke
services. What should you do?

A. Create a class to hold DLL functions and then create prototype methods by using managed 
    code.
B. Register your assembly by using COM and then reference your managed code from COM.
C. Export a type library for your managed code.
D. Import a type library as an assembly and then create instances of COM object.

Answer: A