Final answer:
Option D. Methamphetamine precursors are highly regulated and often illegal to distribute through mail due to their potential use in illegal drug manufacture. Under laws like the CMEA, no methamphetamine precursors can be legally obtained through mail deliveries.
Step-by-step explanation:
The question concerns the legal regulations surrounding the procurement of methamphetamine precursors through mail. Providing methamphetamine precursors through the mail is highly regulated, and in many countries, illegal due to the controlled status of substances that can be used to manufacture methamphetamine, a potent and illegal stimulant.
Under laws like the CMEA, no methamphetamine precursors can be legally obtained through mail deliveries. Therefore, under current regulations, none of the listed amounts can be obtained legally through the mail. Laws such as the United States' Combat Methamphetamine Epidemic Act (CMEA) of 2005 strictly control the sale and distribution of these substances to prevent their use in illegal drug manufacturing.