Solution:We put all the option in blank area and check who create particular pattern
L _ _ A _ _ S _ _ K _ _ L _ _ A
ASLKALSAKA → LASA / LKSA / LKSA / LKAA (No particular pattern followed here)
KSLKALSAKA → LKSA / LKSA / LKSA / LKAA (No particular pattern followed here)
KSKKALSAKA → LKSA / KKSA / LKSA / LKAA (No particular pattern followed here)
But,
KSLKALSAKS → LKSA / LKSA / LKSA / LKSA
Hence, "KSLKALSAKS" is the correct answer.