$4.$ A system has five memory holes $600$Kbytes, $500$Kbyes, $300$Kbytes, $200$Kbytes and $100$Kbytes $($in order, from low memory address to high memory address$).$ There are four processes requiring $112$Kbytes, $212$K$,426$Kbytes and $471$Kbytes $($in order of arrival$).$ What will be the size of the new memory holes left after allocation $($write the hole sizes in order, from low memory address to high memory address$),$ if we use the following scheme?

a$.$ Best Fit scheme

b$.$ Worst Fit scheme

$[2$ Marks$]$

$[2$ Marks$]$

c$.$ If the external fragmentation is defined as "the difference in the size of the biggest and the smallest memory hole", then which of the two schemes has less external fragmentation? $[1$ Mark$]$