Interest income from U.S. Treasury securities is subject to federal income tax but exempt from state and local income taxes. Treasury bills, notes, and bonds are direct obligations of the U.S. government, and their tax treatment is a core fixed-income concept tested on the SIE. Choice C is correct. Choice A is incorrect because Treasury interest is not exempt from federal income tax. Choice B is incorrect because Treasury interest is not subject to state income tax. Choice D reverses the correct treatment and is therefore wrong. This tax distinction is important when comparing Treasury securities with municipal bonds. Municipal bond interest is often federally tax-exempt and may also be exempt from state tax if issued in the investor’s state of residence. Treasury securities follow the opposite pattern: taxable federally, exempt at the state and local level. The SIE outline includes Treasury securities under debt instruments and requires candidates to understand income generation, coupon payments, yield, and the basic features of fixed-income products. Reference: Section 2.1.2 Debt Instruments; Treasury securities; investment income characteristics.