Looking at the given 3x3 grid:
| 7 | 21 | 8 |
|---|---|---|
| 17 | ? | 5 |
| 12 | 1 | 23 |
Let's find the sum of the numbers in each column.
For the first column:
7+17+12=36
For the third column:
8+5+23=36
The pattern shows that each column sums to 36.
For the second column:
21+?+1=36
?+22=36
?=36−22
?=14
Therefore, the value that replaces the question mark is 14.
The answer is Option 2: 14.