Which of the following is a common parasite of cattle?

The choice of a worm as a common parasite of cattle is accurate, as worms, specifically gastrointestinal nematodes, are well-known internal parasites that can significantly impact the health and productivity of cattle. These worms inhabit the digestive tract of the animals, where they can cause issues such as malnutrition, weight loss, intestinal blockages, and overall poor performance. Their eggs are often shed in the feces, which can lead to the contamination of pastures, exacerbating the problem through higher parasite loads in the environment.

While other options like ticks and mites are also parasites that affect cattle, as external parasites, they differ in their habitat and impact. Ticks can transmit diseases and cause irritation, while mites can lead to skin conditions. However, worms are particularly notorious for their impact on the digestive system and overall health, making them a common concern in cattle management.