Option 1 -> This relates to Articles 6 & 7, which deal with migration rights between India and Pakistan before the Constitution commenced.
Option 2 -> Overseas Indians (NRIs/OCIs) are covered under citizenship laws and amendments, not specifically Article 9.
Option 3 -> Article 9 explicitly states that voluntary acquisition of foreign citizenship terminates Indian citizenship.
Option 4 -> Articles 5-8 deal with citizenship rights at the commencement of the Constitution based on various criteria.
Hence, Option 3: Persons who voluntarily acquire foreign citizenship -> Article 9 provides that any person who voluntarily acquires the citizenship of a foreign state shall cease to be a citizen of India. This is a termination clause ensuring that dual citizenship is not permitted under the Indian Constitution -> correct