Answer:
A. Predatory
Explanation:
Roundworm is considered as parasitic infection that has tendency to hurt the human or host gut, most specifically, when they are in large numbers in the host body.
The symptoms associated with roundworm is bowel obstruction, however, they survive in humans by feeding from human body and at the same time reproducing, thereby, increasing in numbers, which can make it's symptoms quickly noticeable.
Hence, roundworm can be described as PREDATORY, as it feeds on the host or human body to survive.