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

#include <iostream>
#include <deque>
using namespace std;
int main ()
{
    deque<int> mydeque;
    int sum (0);
    mydeque.push_back ( 10 );
    mydeque.push_back ( 20 );
    mydeque.push_back ( 30 );
    while (!mydeque.empty())
    {
        sum += mydeque.back();
        mydeque.pop_back();
    }
    cout << sum << '\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