The average time necessary for the correct sector of a disk to arrive at the read write head is _____

ANS:C - Rotational delay

Access time is the time between when one access request has begun and when the next one can begin.

Seek time is the time it takes for the head to move to the data area sought.

Seek time is a component of access time, and will therefore always be smaller. Note, however, that these times as given in specifications will always be averages, since the seek time can vary wildly, depending on how far the head is from the data area it needs to read or write.