Which statement lists the three components of the disease triangle?

• A. Favorable environment; Virulent pathogen; Susceptible host
• B. Moisture; Temperature; Susceptible species
• C. Beneficial microbes; Host resistance; Pathogen virulence
• D. Weather patterns; Plant genetics; Soil type

Answer: (A)

The disease triangle shows that disease occurs only when three elements meet: a susceptible host, a virulent pathogen, and environmental conditions that favor disease development. The statement captures exactly these three components. A favorable environment provides the right moisture, temperature, and other conditions that allow infection and spread. A virulent pathogen has the capacity to cause disease once it encounters a susceptible host. And a susceptible host lacks sufficient defenses, making infection possible. When all three align, disease can occur; if any one is missing or unfavorable, disease development is much less likely.

The other options don’t fit as well because they either emphasize environmental factors alone, mix in host resistance (which is a defense, not a component of the triangle), or introduce factors that aren’t part of the standard three essential elements (like listing only weather patterns or broad factors).