What will be the output of the following C++ code?

#include <iostream>
using namespace std;
class BaseClass 
{
    int x;
    public:
    void setx(int n) 
    {
        x = n;
    }
    void showx() 
    {
        cout << x ;
    }
};
class DerivedClass : private BaseClass
{
    int y;
    public:
    void setxy(int n, int m)
    {
        setx(n);      
        y = m;
    }
    void showxy() 
    {
        showx();       
        cout << y << '\n';
    }
};
int main()
{
    DerivedClass ob;
    ob.setxy(10, 20);
    ob.showxy();
    return 0;
}

What does the 'sizeof' operator return in C++?

A. Size of a data type in bits

B. Size of a data type in bytes

C. Size of a variable in bytes

D. Size of a variable in bits

Which of the following is not a fundamental data type in C++?

A. Char

B. Float

C. String

D. Double

What is the purpose of the 'static' keyword in C++?

A. To declare a variable with dynamic storage duration

B. To declare a constant

C. To declare a variable with external linkage

D. To declare a variable with static storage duration

What is the difference between '++i' and 'i++' in C++?

A. None of the above

B. They both have the same effect

C. '++i' increments the value of 'i' before returning it, while 'i++' increments the value of 'i' after returning it

D. '++i' increments the value of 'i' after returning it, while 'i++' increments the value of 'i' before returning it