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 . 

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