Column C: C3-C2=4, sum=14 -> only (C2,C3)=(1,5) works giving C1=8. Column A (no odd digits, 8 used in C) = {2,4,6}. Column B = {3,7,9}. Row1: A1+B1+8=17 -> A1+B1=9; testing rules (2 not with 8 in row1) gives A1=6,B1=3. Remaining: A2,A3={2,4}; B2,B3={7,9}. Rule: 9 not immediately below 3(B1) -> B2≠9 -> B2=7,B3=9. Rule: 7's left neighbour not 4 -> A2≠4 -> A2=2,A3=4.
Final grid: Row1:6,3,8; Row2:2,7,1; Row3:4,9,5. 9 is at B3.
Final Answer: B3, option (2).