Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
we reserve the right to refuse or cancel orders at any time and at our sole discretion . 

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