Backtracking on Data Structure and Algorithms related Questions and Answers

Question :   Of the following given options, which one of the following does not provides an optimal solution for 8-queens problem? 1. (5,3,8,4,7,1,6,2) 2. (1,6,3,8,3,2,4,7) 3. (4,1,5,8,6,3,7,2) 4. (6,2,7,1,4,8,5,3) Answer :   2 - (1,6,3,8,3,2,4,7)