The sentence that uses the comma correctly is
B. Shivering from the cold, we decided to kindle a blaze in the fireplace.
Here's how the others should be written.
A. While you are waiting for the snow to melt, please do not run on the sidewalks.
C. After the storm, many inches of snow had accumulated on the lawn.
D. Oh, let's make some hot cocoa in the kitchen.
Hope this helps.
