Which of the following is a sentence fragment?

In this unit we learned about arguments and rhetoric. in an argument we use ,not informal language

When you don’t understand a concept during the lecture, it’s to flag it in your notes and leave a blank space so you can fill in more

Which sentence has a correctly placed participial phrase? a. we read about a pizza on the menu covered in pepperoni. b. covered in pepperoni, we read about a pizza on the menu. c. we, covered in pepperoni, read about a pizza on the menu. d. we read about a pizza covered in pepperoni on the menu.