Which sentence contains a comma splice?

Responses
A Flags usually represent nations, but they are also used to send messages.
B Jack, the captain of the team, called a team meeting for Saturday, September 12.
C Although most people in the ancient world lived in plain houses, the palace at Knossos had bathrooms.
D A storm front will move into North Georgia on Thursday, however it should be sunny and clear by the weekend.

D A storm front will move into North Georgia on Thursday, however it should be sunny and clear by the weekend.