Which of the following changes to UK tax policy would increase vertical equity: Select one: a. A reduction in the basic rate tax band to finance a reduction of the top rate of income tax. O b. Reduction in the income tax rate on interest financed by an increase in the tax rate on dividends. O c. Simplification of the VAT rules so that there is only one rate of VAT of 15% (no exempt or zero-rated supplies). O d. An increase in capital gains annual exemption financed by an increase in the top rate of capital gains tax