First, let's look at condition (2) and (3). Each row and column must be an odd three-digit multiple of 3 that is not a multiple of 9. The only odd three-digit multiples of 3 are 111, 333, 555, 777, and 999.
Since each digit can only be used once, the only possible combinations for the rows and columns are:
Row 1: 333
Row 2: 555
Row 3: 777
Column 1: 111
Column 2: 777
Column 3: 999
Now, let's look at condition (4). Diagonal A, read from lower-left to upper-right, must be an odd three-digit multiple of 9. The only odd three-digit multiples of 9 are 117, 135, 333, 369, 711, and 999.
Since 333 is already being used in Row 2, we can eliminate it as a possibility for Diagonal A.
That leaves us with the possibilities for Diagonal A:
117 (Row 1, Column 1)
135 (Row 3, Column 1)
369 (Row 1, Column 3)
711 (Row 3, Column 3)
999 (Row 2, Column 2)
Now, let's look at condition (1): Each digit from 1 through 9 is used exactly once.
Since the only remaining digits are 2, 4, 6, and 8, we can determine the placement of these digits:
Row 1: 33328671
Row 2: 55542896
Row 3: 77796814
Now, let's determine the resulting three-digit number when diagonal B is read from upper-left to lower-right.
The digits in Diagonal B are 1, 9, and 6. Therefore, the resulting three-digit number is 196.
So, the answer is 196.