Which of the following represents a voluntary act in a general intent crime?

In the context of general intent crimes, a voluntary act refers to an action that is performed with intention or willfulness, rather than being automatic or compelled by external forces. Intentionally striking another person exemplifies a voluntary act because it involves conscious decision-making and intentional physical engagement. This reflects the classic understanding of criminal liability, where an individual must have the intention to commit the act that constitutes the crime.

The other options illustrate behaviors or conditions that do not align with the concept of voluntary action in the context of general intent. Reflex actions are involuntary and do not involve deliberate control. Actions taken under duress imply that the person is acting under pressure or threat, thereby lacking true voluntariness. A random misstep indicates an unintentional act lacking purposeful engagement. Therefore, intentionally striking another person stands as the clear example of a voluntary act required for establishing general intent in criminal law.