Respuesta :
The sentence with the correct punctuation is B) After the rain stopped, the teenagers played football.
Since you decided to introduce inversion into your sentence (putting the subordinate sentence - After the rain stopped - first, before the main sentence), it needs to be followed by a comma.
Since you decided to introduce inversion into your sentence (putting the subordinate sentence - After the rain stopped - first, before the main sentence), it needs to be followed by a comma.