Final answer:
The correct answer is a) 30 mg.
Step-by-step explanation:
The correct answer is a) 30 mg. Pseudoephedrine is a decongestant commonly found in over-the-counter cold and allergy medications. In the United States, federal regulations specify that products containing pseudoephedrine should not contain more than 3.6 grams per purchase, which is equivalent to 3600 mg.
However, individual states may have stricter regulations and require the sale of pseudoephedrine to be recorded in a logbook for purchases over a certain threshold, often around 30 mg. Therefore, a purchase of 30 mg or less of pseudoephedrine would not require it to be recorded in a logbook.