Which of the following statements are true in c++?

Which of the following is the valid class declaration header for the derived class d with base classes b1 and b2?

If we create a file by ‘ifstream’, then the default mode of the file is _________

An exception is caused by

Pure virtual functions

What will be the result of the expression 13 & 25?

Declaration of a pointer reserves memory space

Consider the following class definitions:
class a
{
};

class b: protected a
{
};

What happens when we try to compile this class?

A class defined within another class is: