Which of the of the Roman gods / "group of three/" in the Archaic Triad does not have a Greek counterpart?

The correct answer to this question is this: "The Archaic Triad consisted of Jupiter, Mars, and Quirinus. The Greek counterpart of Jupiter was Zeus, and the Greek counterpart of Mars was Ares." The Roman gods "group of three" in the Archaic Triad which does not have a Greek counterpart is none.