This scenario demonstrates manual phishing email verification, which is a foundational detection technique taught in the ECIH Email Security module. Manual verification involves human inspection of email characteristics such as sender address anomalies, mismatched URLs, unusual tone, urgency, and contextual inconsistencies.

Option D is correct because Ethan manually inspects the email by hovering over links, reviewing sender formatting, and evaluating message tone. These actions are key indicators used to identify phishing without relying on automated tools.

Option A relates to encoding analysis, which is not described. Option B involves automated network-based detection. Option C focuses on shortened URLs, which are not present here.

ECIH emphasizes that while automated defenses are important, human verification remains critical, especially for targeted phishing attacks that bypass technical controls. Therefore, Option D correctly identifies the detection approach used.