In the given sequence, the position of the last O is moving forward from every term forward. OOXXXXX ⇒ O’s position 1st and 2nd OXOXXXX ⇒ O’s position 1st and 3rd XOOXXXX ⇒ O’s position 2nd and 3rd XOXOXXX ⇒ O’s position 2nd and 4th XXOOXXX ⇒ O’s position 3rd and 4th That is the correct answer.