To find the odd number, let's examine each option for a common pattern.
Check the sum of digits for each number:
Option 1: 3207→3+2+0+7=12
Option 2: 1308→1+3+0+8=12
Option 3: 2605→2+6+0+5=13
Option 4: 4026→4+0+2+6=12
A number is divisible by 3 if the sum of its digits is divisible by 3.
For options 1, 2, and 4: Sum of digits = 12, which is divisible by 3
For option 3: Sum of digits = 13, which is NOT divisible by 3
Checking divisibility:
3207÷3=1069 ✓
1308÷3=436 ✓
2605÷3=868.33... ✗
4026÷3=1342 ✓
Therefore, 2605 (Option 3) is the odd number as it is the only number not divisible by 3.