In the context of Overseas Citizens of India (OCI), which of the following statements is NOT correct?

A foreign national those who or either of whose parents or grandparents or great grandparents is or had been a citizen of Pakistan or Bangladesh, is not eleigible for it.

An OCI is granted multiple entry visa for a period of ten years only.

An OCI is allowed to undertake all activities except research work for which special permission is required.

Any foreign national who was eligible to become a citizen of India on 26.01.1950 is eligible for it.