Right option is (a) Keyboard and Cursor Control Unit
For explanation I would say: The flight crew can navigate through the pages of FMS and can consult, enter or modify the data via the Keyboard and Cursor Control Unit (KCCU). The Keyboard and Cursor Control Unit (KCCU) enables the flight crew to navigate through the FMS pages on the MFD and enter and modify data on the MFD and can also perform some flight plan revisions on the lateral Navigation Display (ND).
