Which of the following is a category of plant symptoms?

• A. Sign
• B. Girdling
• C. Necrosis
• D. Leafmining

Answer: (C)

Symptoms are the plant’s visible responses to stress, disease, or injury. Necrosis is tissue death in plant tissue, showing up as brown or dead areas where cells have died. It’s categorized as a symptom because it reflects how the plant reacts, rather than evidence of the pathogen or pest itself. A sign would be something you can directly observe from the organism causing the problem, like fungal structures or insect bodies, not the plant’s response. Girdling describes a type of physical injury to a stem or root, which is damage, not a symptom category. Leafmining refers to the pattern of damage caused by leaf‑mining insects, which again is damage evidence from a pest rather than a plant’s symptomatic response. So necrosis best fits as a category of plant symptoms.