Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
if you have any questions about this agreement , please contact us by email : service@nintendo.de . 

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