I can't find any logical relationship in this grid! Could someone help me, please?
\begin{array}{|c|c|c|}\hline 7 & 4 & 1 & 7\\ \hline 4 & 8 & 9 & 3\\ \hline 5 & 6 & 4 & ?\\ \hline 3 & 2 & 6 & 5\\ \hline \end{array}
and choices are
A:
A. 8
B
B. 6
C
C. 5
D
D. 4
This book is the source of the puzzle. The translation of its title is Enhancing the intelligence and educational ability of children and adolescents.