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

#include <iostream> 
#include <algorithm>
#include <vector>
using namespace std;
int main ()
{
    int first[] = {5, 10, 15, 20, 25};
    int second[] = {50, 40, 30, 20, 10};
    vector<int> v(10);
    vector<int> :: iterator it;
    sort (first, first + 5);
    sort (second, second + 5);
    it = set_union (first, first + 5, second, second + 5, v.begin());  
    v.resize(it-v.begin());
    for (it = v.begin(); it != v.end(); ++it)
        cout << ' ' << *it;
    cout << '\n';
    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