Which of the following requires a device driver?

Which of the following disk scheduling strategies is likely to give the best throughput?

Listed below are some operating system abstractions (in the left column) and the hardware components. Which matching pairs is correct?

$$\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,$$List-$${\rm I}$$
(a) Thread $$\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,$$(b) Virtual Address space
(c) File System $$\,\,\,\,\,\,\,\,\,\,$$(d) Signal

$$\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,$$List-$${\rm II}$$
(1) Interrupt $$\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,$$(2) Memory
(3) $$CPU$$ $$\,\,\,\,\,\,\,\,\,\,\,\,\,$$$$\,\,\,\,\,\,\,\,\,\,$$(4) Disk

Which of the following is true?