The question is incomplete as it does not have the options which are:
Solar radiation
Nocturnal pollinators
Moist soil
Grazing animals
Answer:
Nocturnal pollinators
Step-by-step explanation:
Flowers are the reproductive organ of the flower which encloses the reproductive organs in very colourful petals which produce fragrance.
The colour of the petals, the fragrance, the nectar production and the opening of the flower are the result of the evolutionary adaptations under the force of natural selection (pollinators).
The flowers which open at night time are found in the areas where the nocturnal species are found in the highest number. The flower in this area opens at night with fragrance and the white petals so that they can attract the nocturnal pollinators.
Thus, Nocturnal pollinators are correct.