Consider the following statements:

I. Base$-$class constructor functions can be made virtual.

II$.$ Derived class constructor functions can be made virtual.

III. Base$-$class member functions can be made virtual.

IV$.$ Derived class member functions can be made virtual.

Which one of the following options is correct?

Question $19$ options:

Only III is a true statement.

Only IV is a true statement.

Only III and IV are true statements.

All four statements are true.