Choose a compound complex sentence that is correctly punctuated

After they clean their rooms, the boys plan to go swimming but it started to rain
After they clean their room. The boys plan to go swimming. But it started to rain.
After they clean their rooms, the boys plan to go swimming, but it started to rain
After they clean their room the boys plan to go swimming, but it started to rain

1 answer

After they clean their rooms, the boys plan to go swimming, but it started to rain.