From the Discussion of Long-Day and Short-Day Plants, It Is

From the discussion of long-day and short-day plants, it is obvious that "day-neutral" plants

A) flower when the night is shorter than a critical length.
B) flower when the night is longer than a critical length.
C) are not dependent on the length of the night or day for flowering.
D) have short stems or long stems, depending on the photoperiod.
E) have flowers that only open during the daytime.