The correct option is A 601
Alphabets present in the word SACHIN are S,A,C,H,I,N
alphabetical order of the letters present in the given word is A,C,H,I,N,S
If the word starts with the letter A (A _ _ _ _ _) then the remaining 5 position can be filled in 5! ways.
If the word starts with C (C _ _ _ _ _)then the remaining 5 positions can be filled in 5! ways.
If the word starts with H (H _ _ _ _ _)then the remaining 5 positions can be filled in 5! ways.
If the word starts with I (I _ _ _ _ _)then the remaining 5 positions can be filled in 5! ways.
If the word starts with N (N _ _ _ _ _)then the remaining 5 positions can be filled in 5! ways.
If it started with S then the remaining position can be filled with A,C,H,I,N in alphabetical order as on dictionary.
The required word SACHIN can be obtained after the 5×5!=600 ways
i.e. SACHIN is the 601th word.