What is output? #include using namespace std; class School { public: School( ); static int getNextId(); private: int id = 0; static int nextId; }; School::School( ) { id = nextId; nextId += 1; } int School::getNextId() { return nextId; } int School::nextId = 0; int main( ) { School( ); cout << School::getNextId() << " "; School( ); cout << School::getNextId() << " "; School( ); cout << School::getNextId() << " "; School( ); cout << School::getNextId() << " "; return 0; } a. 3 2 1 0 b. 0 1 2 3 c. 4 3 2 1 d. 1 2 3 4