Which of the following is most often true?
a) the ios is stored in flash and copied into ram at startup.
b) the ios is stored in ram and copied into flash at startup.
c) the ios is stored in rom and copied into ram at startup.
d) the ios is stored in rom and copied into flash at startup.

a) The IOS is stored in flash and copied into RAM at startup.

Explanation:

Well,  in most router architectures, the IOS is copied into and run from RAM. This is because of the flash allows the IOS to be upgraded in any moment or allows it  to stores multiple IOS files.

Keep in mind that if the flash memory is empty, the router will try to use a TFTP server to load an IOS image from the network and for the last resort if the TFTP server is unavailable, the router will load the limited version Cisco IOS software image stored in ROM.

it would be a. excessive network collisions or d. slow connectivity between devices those would be my answer.

answer///router;