Answer:
D. An independent clause contains a complete thought and can stand on its own.
Step-by-step explanation:
An independent clause means that it can be said as it's own sentance. For example "I'm going to the movie theater later today." A dependent clause would be something like "When the president arrives." which cannot stand on its own as it has no context, and needs to be finished with a independent clause like "We will celebrate at the city hall."