Explanation:

- Samadhin: A term used to refer to the mother-in-law of one's child. It signifies a relationship created by marriage.

- Chacha: This is a common Hindi term used to refer to the paternal uncle, specifically the father's younger brother.

- Salehars: This refers to brothers-in-law or the brothers of one's wife. It is part of the extended family network through marriage.

- Option 4: All of the above: This option is correct. All three terms are indeed classificatory kinship terms used in Hindi to describe familial relationships formed by blood or marriage.