A. withstand aerodynamic loads and breaking loads
B. reduce drag
C. lowers the weight of an aircraft
D. decrease the drag produced by gear only
The question was asked during an interview for a job.
Question is taken from Gear-Retraction Geometry topic in chapter Landing Gear and Subsystems of Aircraft Design
For explanation I would say: Typical landing gear retraction arrangement includes a diagonal arm. This diagonal arm for nose wheel is called drag brace. Drag brace is used to withstand the breaking loads and aerodynamic loads as well.