Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
please note : section 19 of these terms of service contains an arbitration clause and class action waiver that applies to all airbnb members . 

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