What is the default access modifier of a class and struct in C# if no access modifier is explicitly specified?

Which of the following operators cannot be overloaded in C#?

Which keyword is used to overload an operator in C#?

Which access specifier is used to make a member accessible only in the class where it's defined or inside the derived class.

In C#, classes are reference types.

Can the elements in the collection be modified within the foreach loop?

In C#, given that the index of the last element in an array is 6, what is the length of the array?

Which of the following is NOT a valid way to declare and initialize an array in C#?