What type of disease affects the entire body or several parts of it?

The correct choice describes a systematic disease as one that affects the entire body or multiple systems within the body. This type of disease is characterized by widespread impact, meaning it can involve various organ systems and lead to systemic symptoms rather than localized issues. Examples include autoimmune diseases, where the immune system mistakenly attacks healthy tissue, affecting multiple areas of the body.

In contrast, pathogenic diseases and infectious diseases typically refer to conditions caused by pathogens like bacteria or viruses, which may primarily affect specific parts of the body or manifest in localized infections. Chronic diseases are long-lasting conditions that may be systemic, but the term usually describes the duration and management of the illness rather than its spread throughout the body.