Final answer:
The trombone and bagpipes are medieval instruments that still retain their original shape today.
Step-by-step explanation:
Out of the given options, the correct answer is c. trombone and bagpipes. These two instruments have been used since the medieval period and have managed to retain their original shape to this day. The trombone is a brass instrument with a sliding tube and a bell, while the bagpipes consist of a bag and pipes that produce sound when the bag is squeezed and the pipes are played.
Learn more about Medieval instruments