Explanation:

- Section 32(4) of the Evidence Act deals with statements made in documents, including statements as to the existence of any public right or custom, relevant in certain cases.

- Section 32(7) refers to statements made in documents relating to the existence of any relationship by blood, marriage, or adoption, not specifically about the proof of custom.

- Section 48 explicitly deals with the opinion as to the existence of a custom or right, allowing opinions of persons who would be likely to know of its existence.

- So, while Section 32(4) and Section 48 relate to proof of custom, Section 32(7) does not.

The correct answer is:

- Option:3, section 48 of Evidence Act.