Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
cancellation is effective at the end of the applicable monthly period . 

```
. OPTIONS: ['Limitation of liability' 'Choice of law' 'None' 'Unilateral change'
 'Content removal' 'Contract by using' 'Unilateral termination'
 'Arbitration' 'Jurisdiction'].