The correct option is B 2, 4, 3, 1
The first two letters are KN for all the four words. Based on this, we cannot judge the order of the words.
So, we will start with the third letter.
The 3rd letters of the words are O, A, O, and I.
From this, the first word will be KNACK, and the second one will be KNIT.
Since, both KNOW and KNOB have O as the third letter, we will consider the 4th letter to arrange them.
They are B and W.
So, KNOB will appear in the third place and KNOW in the fourth place.
The correct order is:
KNACK, KNIT, KNOB, KNOW, i.e., 2, 4, 3, 1