Explanation:

- Option 1: Descriptive term

A descriptive term provides details or describes characteristics. "Samadhin" doesn’t fit as it is not used for general descriptions.

- Option 2: Classificatory term

This refers to a term that categorizes or classifies. "Samadhin" is a classificatory term as it identifies a specific familial relationship, specifically referring to the mother of one's son-in-law or daughter-in-law in Hindi culture.

- Option 3: Depends on case-to-case basis

This means usage can vary widely based on context. "Samadhin" consistently refers to a family relation, not situational.

- Option 4: None of above

This implies it fits none of the given categories. However, "Samadhin" clearly classifies a relationship.