I am currently enrolled in your course, “Air Pollution Dispersion Screening Model”. I am writing to bring your attention to a potential issue I encountered in Activity Check 1 (https://learning4life.usm.my/courses/aerscreen/activity_knowledge_check_1/?cl=1&moduleSet=Default).

Specifically, I believe there may be a bug in Question 2. Regardless of the combination of model categories I input, the result is consistently marked as incorrect. Initially, I submitted what I believed to be the correct answer:

• Unsteady-state model: CALPUFF
• Steady-State model: AERMOD, AERSCREEN

However, this was marked as incorrect. I have since tried all possible combinations, but to no avail.

I am unsure of how to proceed. As I understand it, I must answer all questions correctly to advance in the course. I would greatly appreciate your assistance in resolving this issue.