If you need to remove Campaigns and/or Opportunities from Marketing app:

1. Do Steps 14-16 (Lab 1b)

2. Now in the Custom App Edit panel that appears for Marketing, check the Selected Tabs window to find Campaigns and if it's there, then click it to highlight it & click the left-arrow to move it over to the Available Tabs window

3. Now check the Selected Tabs window to find Opportunities and if it's there, then click it to highlight it & click the left-arrow to move it over to the Available Tabs window

4. Click Save at the bottom

5. Re-grade by using the App Launcher to open the Grader App and follow instructions to run the scoring routine again and then be sure to reload the page to see the updated error list & grade certificate