Which assessment is crucial for older adults starting a new medication to prevent adverse drug events?

A. Assessment of past surgical history: While surgical history may influence some medication decisions, it is not the primary factor in preventing adverse drug events when starting new medications. B. Height and weight recording: Accurate height and weight are important for calculating certain drug dosages, but most older adults do not require frequent adjustments based solely on these parameters. C. Blood pressure measurement: Blood pressure assessment is important for medications that affect cardiovascular function, but it does not address the broader issue of safe medication use, adherence, or understanding. D. Evaluation of medication knowledge and understanding: Ensuring that older adults understand their new medication, including dosage, timing, potential side effects, and interactions, is crucial in preventing adverse drug events.