Which excerpt from a concluding paragraph about banning plastic bags is written in a formal tone

A. Plastic bags should seriously be banned from all stores across the United States
B. Americans use 100 billion plastic bags each year. We mush step up our game and stop using so many single-use plastic bags
C. Bringing reusable bags to the grocery store is one way the average citizen can help reduce the use of plastic bags
D. Like I said, plastic bags are terrible and absolutely shouldn’t be used by anyone

C. Bringing reusable bags to the grocery store is one way the average citizen can help reduce the use of plastic bags