What is the default access modifier for a class in C# if no access modifier is specified?

Solution (By Examveda Team)

The correct answer is Option A: internal.

Let's break down what an "access modifier" means in C# for a beginner:
Imagine you're building a program in C#. Your program is made up of different parts, like a house is made up of different rooms. A class is like one of these rooms, and it contains all the instructions and data for a specific part of your program.

An access modifier is like a lock on the door of your room (class). It controls who can "see" or "use" that room from other parts of your house (program) or even from other houses (other projects/assemblies).

When you write a class like this:
class MyClass
{
// ... your code here
}

You haven't put any specific "lock" (access modifier) on it. In C#, when you don't specify any access modifier for a top-level class (meaning a class that isn't inside another class), it automatically gets the internal access modifier.

What does internal mean?
It means your class (MyClass in our example) can be accessed and used by any other code within the same assembly. Think of an assembly as your entire project or application. So, if you have other classes within the same project, they can use MyClass. But if you try to use MyClass from a *different* project (a different application or library), you won't be able to.

Let's quickly see why the other options are not the default for a class:
private: This is the default access modifier for *members* (like variables or methods) *inside* a class, but not for the class itself when it's at the top level. A top-level class cannot be declared as private.
public: This means the class can be accessed from *anywhere*, even from other projects. It's not the default; you have to explicitly type public class MyClass.
protected: This modifier is mainly used for members within a class and for nested classes. It allows access within the defining class and by classes that inherit from it. It's not the default for a top-level class.

So, the key takeaway is: For a class in C# that isn't nested inside another class, if you don't specify an access modifier, it is internal by default. This keeps it visible only within its own project.