Which of the following is classified as a virus?

Hepatitis is classified as a virus because it refers to a group of viruses that primarily infect the liver, leading to hepatitis, an inflammation of that organ. The most notable types include Hepatitis A, B, C, D, and E viruses, each with different transmission methods and implications for public health. These viruses can cause significant health issues, including acute and chronic liver diseases.

In contrast, the other options listed are all types of bacteria. Shigella, Clostridium, and Salmonella are bacterial pathogens that can cause various gastrointestinal diseases but do not fall under the virus category. Understanding the differences between viruses and bacteria is crucial in the field of wastewater management, as it directly impacts treatment strategies, health regulations, and public safety measures regarding pathogen control and disposal.