Answer: a. Photo-periodism
Explanation:
The relative length of the day is considered as a major factor in the development of plants, particularly in sexual reproduction. The plants were grouped considering that the flowering and fruiting occurs only when the length of the day is within certain limits so that these phases are achieved only in certain times of the year. Therefore, some species respond to long days, while others respond to short days, and still, others are capable of responding to all day lengths. The name and meaning of each group became as follows:
Short Day Plants: They are the species that bloom in smaller photoperiods than a critical maximum.
Long day plants. These are the species that bloom in larger photoperiods than a critical minimum.
Neutral day plants: They are those that bloom in a wide range of the photoperiod.
