(a) Explain the nature and purpose of the withholding tax system in Nigeria. (5 marks) (b) State the withholding tax rate applicable to each of the following payments made by a Nigerian company, and indicate in each case whether the tax is a final tax: (i) dividend paid to a corporate shareholder; (ii) rent on office premises; (iii) fees paid to a firm of consulting engineers; (iv) payment under a supply contract; (v) directors' fees. (10 marks)