Which of the following is the fifth largest modern constellation?

The fifth largest modern constellation is Hercules. This constellation covers an area of approximately 1225 square degrees, making it one of the larger constellations in the night sky. Hercules is notable not only for its size but also for its rich mythology and association with various astronomical features, including the famous Great Hercules Cluster (M13) and other significant deep-sky objects. Its visibility and positioning in the celestial sphere have made it a prominent constellation throughout the history of astronomy.

The other constellations mentioned, while significant in their own right, do not cover as vast an area as Hercules does, thus confirming Hercules's rank among the largest modern constellations.