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

#include <iostream>
#include <stack>
using namespace std;
int main ()
{
    stack<int> mystack;
    mystack.push(10);
    mystack.push(20);
    mystack.top() -= 5;
    cout << mystack.top() << endl;
    return 0;
}

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

A. Char B. Float C. String D. Double

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

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