While preparing a short explanation about seasonal changes in nature, a student records these notes: (1) Phenology is the study of the timing of recurring biological events. (2) Examples include flowering, leaf fall, bird migration, and insect emergence. (3) Phenology records can show how seasonal timing changes over years. (4) Volunteers may report the date when a local tree first blooms. The student wants to define the term phenology for citizen scientists tracking local plants. Which choice most effectively uses relevant information from the notes to accomplish this goal?