What is the civil penalty for possession of less than one ounce of marihuana in Massachusetts for an adult?

In Massachusetts, the decriminalization of the possession of less than one ounce of marihuana for adults means that there is a civil penalty associated with this action. Specifically, the law stipulates that an adult found in possession of less than one ounce will incur a civil fine of one hundred dollars. This approach reflects a shift toward treating marijuana possession more like a civil violation rather than a criminal offense, which aligns with broader trends in drug policy reform in various states.

Other options, such as five hundred or one thousand dollars, represent penalties that would apply in other contexts or more serious violations regarding marijuana, but they are not applicable for this specific scenario of possession of less than one ounce. The option indicating no penalty is also incorrect, as there is a clearly defined civil penalty in place for this specific action. Therefore, the one hundred dollar civil penalty is the correct understanding of the legal framework governing marihuana possession for adults in Massachusetts.