Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
( i ) `` basics '' free trial : a free-of-charge program , which gives unlimited access to ten days of our `` foundation course . '' 

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