By seeing which operator thus this C++ program stops getting the input?

#include <iostream>
#include <fstream>
using namespace std;
int main ()
{
    char ch;
    streambuf * p;
    ofstream os ("test.txt");
    pbuf = os.rdbuf();
    do {
        ch = cin.get();
        p -> sputc(ch);
    } while (ch != '.');
    os.close();
    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