Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
you may close your account at any time by contacting customer support . 

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