Final answer:
The option that doesn't belong to the Ethiopian citizenship requirements is 'Insufficient and unlawful source of income to maintain himself and his family.' Citizenship typically necessitates a lawful income and the ability to communicate in a national language.
Step-by-step explanation:
To answer the question regarding Ethiopian citizenship criteria, the option that does not belong is 'Option 4: Insufficient and unlawful source of income to maintain himself and his family.' Generally, countries require applicants for citizenship to have a lawful and adequate source of income. In contrast, options 1, 2, and 3 are typical requirements for naturalization in many countries, including Ethiopia. The applicant needs to reach the age of majority (Option 1), have lived in the country for a specified period, which can be around four years (Option 2), and be able to communicate in one of the national languages (Option 3).