Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
minors may only participate in an experience , event or other host service if accompanied by an adult who is responsible for them . 

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