Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
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you must be 18 years of age , or the age of majority in your province , territory or country , to sign up as a registered user of the products . 

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