60.
The answer is: C
Explanation
The correct option is C: Residence.
Articles 15 and 16 of the Indian Constitution prohibit discrimination on the grounds of religion, race, caste, sex, or place of birth, but not on the grounds of residence. However, Article 16 (3) allows Parliament to make any law prescribing any requirement as to residence within a State or Union territory prior to employment or appointment under that State or Union territory.
This provision is meant to protect the interests of the local population and to ensure that they have adequate representation in the public services. Therefore, residence is a ground on which the State can discriminate, subject to the law made by Parliament.