Which type of engineering design uses an already existing design? A. top-down design
B. spiral design
C. bottom-up design
D.
incremental design

The correct option is;

C. Bottom-up design

Explanation:

The bottom-up design is meant for system redesign or re-engineering of an existing design involving component upgrading or legacy systems replacement

The bottom-up design approach is also meant for applications where there is a new interface requirement for the original system in order to determine the functionality of the newly combined systems and also where a novel component is incorporated into the existing design.

The bottom-up approach starts with the analysis of the interoperability of the components to the modules and eventually the analysis of the system requirements.

can you make it more obvious. i can't see it properly