Microsoft Certified Solutions Developer (MCSD) Practice Test 2025 – Complete Exam Prep

The InternalsVisibleToAttribute is a feature in .NET that allows developers to expose the internal members of a specific assembly to another designated assembly. By applying this attribute, you can grant access to internal types and members, which are usually not accessible outside their own assembly, to other assemblies defined in the attribute. This is particularly useful in situations where you want to enable unit testing or shared functionality without making those internal components publicly accessible to every assembly.

This mechanism allows tighter control over which assemblies can access certain parts of your code, aiding in encapsulation while still facilitating collaboration between assemblies that need to interact closely. For instance, it’s often employed to let test assemblies access internal members for testing purposes, thus maintaining the integrity of the public API.

The other options do not accurately describe the purpose of the InternalsVisibleToAttribute. Hiding internal workings or making all members public are not functions of this attribute, nor does it have any effect on the performance of a class library. The focus of InternalsVisibleToAttribute is solely on managing access to internal members between assemblies.