The answer is: A. Serve tea
hisashige tanaka's robots are simple mechanical dolls that is deisnged to move in one direction without being controlled by humans.
They are often used as an attraction and made to perform single linear movements (such as bringing tea on top of a tray for the guests)
Even though the robot is not advanced as what we had to day (it was created in 1800s), it was a considered as a foundation that developed japanese robotyic field ever since
