Plant diseases are categorized into four major pathogen groups: fungi, bacteria, viruses, and nematodes. Nematodes fit this set as they are microscopic roundworms that attack plant roots, causing damage that leads to poor nutrient and water uptake and stunted growth. That’s why this option is included among the four major plant pathogen groups. Algae aren’t listed as a major plant-pathogen group in this framework; lichens aren’t pathogens at all but a mutualistic combo of fungi and algae; molds are a form of fungi, not a separate major group.

Site-specific restrictions are extra rules printed on a pesticide label that limit how the product can be used for particular crops, pests, or geographic areas. They are mandatory directions that tell you where, when, or on which crops the product may or may not be used, beyond the general instructions. These restrictions help protect sensitive crops, pollinators, water, and other sensitive environments. They are not optional tips, nor storage notes or toxicity warnings. For example, a label might authorize use on one crop but forbid it on another, or restrict application within a certain distance of water or in specific counties.

Identifying insects relies on looking at a combination of body features, not just one trait. Wings, legs, and mouthparts each provide important clues about which group an insect belongs to. Wings can indicate different orders or life stages based on whether they are present, absent, or the type and arrangement of the wings. Legs show not only that there are six legs but also characteristics like spines, leaf-like structures, or jumping adaptations that help distinguish groups. Mouthparts reveal feeding strategies and taxonomic relationships, with types such as chewing, piercing-sucking, siphoning, or lapping offering strong diagnostic signals. Because any single feature can be misleading on its own, using all three together gives the most reliable identification. Some insects may lack wings or have specialized mouthparts, but the combined information from wings, legs, and mouthparts remains a core approach to identifying insects. That's why all of the above is the best answer.

Storing pesticides safely hinges on keeping the product identifiable, preventing dangerous interactions, and avoiding contamination of food and water. Keeping pesticides in their original containers preserves the label information—active ingredients, hazards, and specific storage instructions—so you know exactly what you have and how to handle it safely. Storing them with other incompatible chemicals raises the risk of chemical reactions, fires, or releases of toxic gases, which can endanger people and the environment. And keeping pesticides away from food, feed, and water supplies prevents accidental contamination of edible items and drinking water. Other ideas like noting a date/time don’t address these critical safety aspects, while soil type at the application site or the rate/amount relate to use, not to how the product should be stored.