Concept:The reticulated python is recognized as the world's longest snake species, reaching lengths over 33 feet.
Explanation:Reticulated pythons can grow up to about 33 feet in length, making them the longest snakes on Earth.
Green anacondas are the heaviest, but they are shorter, usually under 29 feet.
Vipers are small, averaging only about 2 feet.
Boas are medium‑sized, typically around 10 feet long.
Comparing these lengths shows that the reticulated python clearly exceeds all others in total length.
Answer:Reticulated pythons (Option D).