The free-space list can be implemented using a bit vector approach. Which of the following is a drawback of this technique?

A、A)Totraversethelist,eachblockmustbereadonthedisk.
B、B)Itisnotfeasibletokeeptheentirelistinmainmemoryforlargedisks.
C、C)Thetechniqueismorecomplicatedthanmostothertechniques.
D、D)Thistechniqueisnotfeasibleforsmalldisks.