Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
we may offer free trials or other limited versions of services so that you can preview services before you purchase the full version . 

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