Which hdparm command-line options will set an IDE hard disk to use both DMA and 32-bit I/O
support?

A.
-p 1 -A 1

B.
-f -g

C.
-L 1 -i 1

D.
-d 1 -c 1

E.
-L 1 -i 32

Explanation:
From the man pages:
hdparm provides a command line interface to various hard disk ioctls supported by the stock Linux
ATA/IDE device driver subsystem.
-c Query/enable (E)IDE 32-bit I/O support. A numeric parameter can be used to enable/disable 32-bit
I/O support: Currently supported values include 0 to disable 32-bit I/O support, 1 to enable 32-bit
data transfers, and 3 to enable 32-bit data transfers with a special sync sequence required by many
chipsets.
-d Disable/enable the “using_dma” flag for this drive. This option now works with most combinations
of drives and PCI interfaces which support DMA and which are known to the kernel IDE driver. It is
also a good idea to use the appropriate -X option in combination with -d1 to ensure that the drive
itself is programmed for the correct DMA mode, although most BIOSs should do this for you at boot
time.