Which of the Following Statements About Flowering Plants Is True

Which of the following statements about flowering plants is true?

A) A short-day plant requires nights longer than a certain critical period to trigger flowering.
B) A long-day plant requires nights shorter than a certain critical period to inhibit flowering.
C) A short-day plant requires daylight of short wavelengths.
D) A long-day plant requires long wavelengths during the night.
E) A long-day plant requires long days alternating with short days.