What Mistake Prevents the Following Class Declaration from Functioning Properly

Multiple Choice

What mistake prevents the following class declaration from functioning properly as an abstract class?
Class Shape
{
Public:
Virtual double print) const;
Double area) const { return base * height; }
Private:
Double base;
Double height;
};

A) There are no pure virtual functions.
B) There is a non-virtual function.
C) private variables are being accessed by a public function.
D) Nothing, it functions fine as an abstract class.