Concept:Day-neutral crops are non-photoperiodic plants; their flowering does not depend on the relative lengths of day and night.
Explanation:Photoperiod is the length of daylight compared with the length of darkness.
In short-day and long-day crops, flowering is triggered by specific photoperiod conditions.
Day-neutral crops have no such photoperiodic requirement.
They flower after reaching a certain stage of growth, even if the daylength is longer than the night or if the daylength changes.
Extremely low or high temperatures are not the deciding factor for classifying them as day-neutral.
Therefore, day-neutral crops flower irrespective of whether the day is longer than the night.
Answer:A. daylength being longer than the length of night