Exp. (d)
In the word 'SACHIN', order of alphabets is A,C, H,I,N and S.
Number of words start with A=5 ! , so with C,H,I,N.
Now, words start with S and after that ACHIN are in ascending order of position,
so 5.5! =600 words are in dictionary before words with S start and position of this word is 601.