The correct answer is (b). A suit involving purely religious rights is not a suit of civil nature.
A suit of civil nature is a legal action that is brought by one person against another in order to resolve a dispute. The dispute can be about anything, but it must be something that can be resolved by the courts.
A suit involving purely religious rights is not a suit of civil nature because it is not something that can be resolved by the courts. The courts cannot interfere in religious matters.
The other options are all suits of civil nature. A suit relating to rights of worship is a suit that is brought by someone who believes that their right to worship has been violated. A suit for rent is a suit that is brought by a landlord against a tenant who has not paid rent. A suit for rights to hereditary office is a suit that is brought by someone who believes that they have the right to inherit an office.
I hope this helps! Let me know if you have any other questions.