Refer to the exhibit to answer the question.

The system includes classes as shown in the Exhibit, with each separately providing information
that is graphed. Two examples are shown, for Stock prices and Store transactions. What is the
BEST refactoring to improve the system design?

A.
Create a common GraphObject class, as shown in C, to be responsible for the graphing
functionality.

B.
No redesign is needed, since these capabilities are very different and should thus remain
separate as currently designed.

C.
Create a Graphable interface, as shown in B, to create a graphing type.

D.
Create a common superclass, as shown in A, to create a graphing framework.