Some offenses can be proved by alternative theories. For example, impaired driving occurs when a person drives while (1) while under the influence of an impairing substance, (2) after consuming a sufficient quantity of alcohol that the person has an alcohol concentration of 0.08 or more at any relevant time after the driving, or (3) with any amount of a Schedule I controlled substance or its metabolites in his or her blood or urine. See Jessica Smith, North Carolina Crimes: A Guidebook on the Elements of Crime (7th ed. 2012). The three options noted above constitute three separate theories upon which an impaired driving conviction can rest. Similarly, kidnapping occurs when a person (1) confines, (2) restrains, or (3) removes a person and other elements are satisfied. Id. The three options—confines, restrains, or removes—constitute three separate theories upon which a kidnapping conviction can rest. Sometimes alternative theories are bound up in the definition of an element of an offense. For example, first-degree sexual assault with a child requires, among other things, that the defendant engage in a “sexual act” with the victim. Id. The term sexual act is defined to include, in part, (1) cunnilingus, (2) analingus, (3) fellatio, and (4) anal intercourse. Id. These acts constitute separate theories that can support a sex offense conviction.