Do All Flowering Plants Act as Either Short- or Long-Day

Multiple Choice

Do all flowering plants act as either short- or long-day plants with respect to flowering?

A) Yes, all flowering plants act as either short- or long-day plants.
B) Yes, but some flowering plants can switch between acting as short- or long-day plants.
C) Yes, but some plants switch from short-day to long-day as they age.
D) No, some plants flower only when the day length and night length are exactly equal.
E) No, some plants flower independently of day length.