Vernal window passage - Assumptions

Evaluate both assumptions carefully against the text [cite: 2714, 2715]:

Assumption 1 specifies "Global warming" causes early, elongated springs. However, the passage only mentions "warmer winters with less snow" as a localized observation, without identifying macro-level global warming as the explicit driver.

Assumption 2 generalizes that early/longer spring is "not good for bird populations". The text states that early ice-melt causes birds not to return, which delays or lengthens ecological events. It highlights a disruption in the ecological timetable, but it does not evaluate the overall health, survival, or well-being of the bird population itself. Therefore, neither assumption can be validated[cite: 3670, 3671].

Answer: (d).