A day-neutral plant is a plant that flowers regardless of the amount of light of daylight it receives. Corn and rice are examples day-neutral plantsthat will bloom whether the day is long or short.

Day neutral plants refer to plants that are not influenced by the length of daylight and are capable of flowering under various photoperiods. The correct answer is option 'B' - flowering in all possible photoperiods.

Explanation:
Day neutral plants are not dependent on the duration of daylight for flowering. Unlike short-day plants that require long nights or long-day plants that require short nights to induce flowering, day neutral plants can flower regardless of the photoperiod. Here is a detailed explanation of the options:

a) Loss of activity during daytime:
This option is incorrect as day neutral plants do not exhibit a loss of activity during the daytime. They are active and capable of performing various physiological processes throughout the day.

b) Flowering in all possible photoperiods:
This option is correct. Day neutral plants have the ability to flower under any photoperiod, whether the duration of daylight is short or long. They are not affected by the length of daylight and do not require specific day lengths to initiate the flowering process.

c) Overactive during daytime:
This option is incorrect. Day neutral plants do not exhibit overactivity during the daytime. They have a balanced activity level throughout the day and do not show any specific pattern of increased activity during daylight hours.

d) No flowering in any photoperiods:
This option is incorrect. Day neutral plants are characterized by their ability to flower in various photoperiods. They do not require specific day lengths and are not restricted to certain photoperiods for flowering.

In conclusion, day neutral plants are not influenced by the duration of daylight and can flower in all possible photoperiods. They are not limited by specific day lengths and have the flexibility to initiate flowering under different light conditions.