Refer to the exhibit to answer the question.

Assume the following class dictionary: Stock: Equity ownership of a portion of a company. Bond: A
loan made to a company that is repaid with interest at a future date. There is a new requirement to
extend the “trade stock” use case by supporting bond trades. Which figure in the Exhibit is the
BEST design to support these new types of objects?

A.
Figure A

B.
Figure D

C.
Figure C

D.
Figure B