Under Section 91 IEA, when the terms of a contract have been reduced to the form of a document, evidence of those terms must be given:

1. Section 91 IEA: 'When the terms of a contract, or of a grant, or of any other disposition of property, have been reduced to the form of a document, and in all cases in which any matter is required by law to be reduced to the form of a document, no evidence shall be given in proof of the terms of such contract, grant or other disposition of property, or of such matter, except the document itself, or secondary evidence of its contents in cases in which secondary evidence is admissible under the provisions hereinbefore contained.' 2. Section 92 IEA then bars oral evidence to contradict, vary, add to, or subtract from, the terms of such document. 3. Together they enact the 'best evidence rule' for documentary contracts. 4. Exceptions to Section 92 are listed in its six provisos (fraud, separate oral agreement on a distinct matter, etc.). 5. Hence option B is correct. _Source: Indian Penal Code 1860 / Code of Criminal Procedure 1973 / Indian Evidence Act 1872 (Bare Acts, indiacode.nic.in) — Indian Evidence Act, Sections 91-92_