Concept:Entomology is the scientific study of insects, including insect pests that attack crops.Explanation:The question asks for the study of insect pests of crops.Since insect pests belong to the class Insecta, the field that focuses on their study is entomology.Pathology deals with plant diseases, agronomy deals with crop production and soil management, and synecology deals with ecological communities.Therefore, the correct discipline for studying insect pests is entomology.Answer:A. entomology