(a) Separate accounting;
(b) The exclusion of any one or more of the factors;
(c) The inclusion of one or more additional factors which will fairly represent the taxpayer’s business activity in this state; or
(d) The employment of any other method to effectuate an equitable allocation and apportionment of the taxpayer’s income.
(2) The department may adopt rules to promote uniformity and consistency with other states in the application of the Uniform Division of Income for Tax Purposes Act. [Formerly 314.670]