While on an Intersession Course in Tropical Ecology, Kris Pulls

While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit) . The 1-metre-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow) .
-The organism was found to have two lungs, but the left lung was much smaller than the right lung. Kelly added that the herpetology instructor had said that in most snakes, the same condition exists. If the size difference between the lungs in this organism is not a shared ancestral characteristic with its occurrence in snakes, then its existence in this organism is explained as which of the following?

A) a result of convergent evolution
B) a result of convergent evolution and a similar adaptation to a shared lifestyle or body plan
C) an example of homologous structures and a similar adaptation to a shared lifestyle or body plan
D) a similar adaptation to a shared lifestyle or body plan and a result of having identical Hox genes