Explanation:

1, 2 and 3 only

Special Category status for a state is not officially defined, but historically, it has been associated with certain criteria. Some of the commonly considered criteria include:

Hilly and difficult terrain: States with challenging geographical features, such as hills and difficult terrain, are often considered for special category status.

Strategic location along international borders: States located along international borders, especially those with strategic importance, may be considered for special category status.

Non-viable nature of State finances: States with limited financial resources and a weak revenue base may be considered for special category status to receive additional financial assistance.

The other criteria mentioned (High population density and States having ageing population) are not typically included in the criteria for granting Special Category status to a state