Which Destiny expansion added the Dreadnaught in Saturn's rings?

The Taken King added the Dreadnaught, a massive Hive ship positioned within Saturn's rings.

Released on September 15, 2015, The Taken King was Destiny's third expansion and the major centerpiece of the game's Year Two. Its story follows Oryx, the Taken King, who seeks revenge after Guardians defeat his son Crota in the earlier expansion The Dark Below.

The Dreadnaught became a new playable destination with Patrol activities, secrets, enemies, and the Court of Oryx public activity. It also hosted the King's Fall raid, in which a fireteam boards Oryx's ship and battles through its fortress-like interior. Its placement in Saturn's rings made it one of Destiny's most distinctive locations.

The other options belong to different parts of the original game's expansion history. The Dark Below focused on Crota, House of Wolves centered on the Fallen and added the Prison of Elders, and Rise of Iron later introduced the SIVA conflict. None added the Dreadnaught.