Co-operative bank inclusion expands income-tax treatment to exclude primary societies while aligning definitions with existing provision. Inserts wording into clause (a) and the long line of section 43D to include a co-operative bank, other than a primary agricultural credit society or a primary co-operative agricultural and rural development bank. Adds an Explanation clause defining those three terms by reference to the meanings assigned in the Explanation to the related statutory provision, ensuring consistent application of the added language.