What constitutes public indecency?

Public indecency is primarily defined by acts that violate community standards of decency and morality, particularly involving sexual conduct. The correct choice reflects this definition, as it specifically identifies behaviors that involve sexual penetration or sexual conduct intended to arouse or satisfy sexual desire. This aligns with typical legal definitions where public indecency includes actions that are overtly sexual in nature and occur in a public setting, thereby disrupting the peace and moral standards of society.

The other options, while they may involve public scenarios, do not meet the criteria for public indecency. Verbal arguments and conversations about personal relationships do not inherently involve sexual content or intent. Changing clothes in public, unless it involves lewd conduct or indecent exposure, typically does not rise to the level of public indecency. Therefore, the behavior described in the correct answer is the only option that meets the legal threshold for this offense.