Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
tripadvisor and some of its affiliates act as marketplaces to allow travelers to enter into vacation rental agreements or rental transactions with property owners and managers ( each , an `` advertiser '' ) . 

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