(a) A corporation subject to the tax imposed by Section 40-18-2 shall pay a tax equal to six and one-half percent of the taxable income of the corporation, as defined in this chapter.
(b) If the taxpayer elects to file an Alabama consolidated return under Section 40-18-39, the tax shall be assessed, collected, and paid annually for each taxable year at the rate specified in subsection (a), upon and with respect to the taxable income of the Alabama affiliated group.