Amend the Keffer Amendment to CSHB 3 on page 9, between lines 8 and 9, by inserting: Sec. 251.021. CREDIT FOR CERTAIN RESEARCH AND DEVELOPMENT ACTIVITIES. (a) A business that elects to pay the tax under this chapter is entitled to a credit against the tax imposed under this chapter in the amount and under the conditions and limitations provided by Subchapter 0, Chapter 171, for certain research and development activities. (b) The credit may not exceed 50 percent of the amount of tax due under this chapter for a calendar year.