Answer:
Invertebrates have a very quick life cycle and die very easily, as a result, they evolve very quickly into many different types of animals. also, they are often very small and their ecosystems are subject to much quicker change than that of vertebrates, meaning that mutations in their genes become relevant more often. Many invertebrates span very large areas (sea animals span most of the oceans, insects span entire continents) and so they evolve to be different species in different places.
Or
They do not have bones, they live on water or land, they can have soft bodies or exoskeletons, and others are parasites.
Petals: The main function of petals is to attract pollinators
Anther: It produces and contains pollen, the male sperm in plants.
Filament: it's the sterile part of the male reproductive organ, and its main function is to sustain the anther.
Pollen: it's the grain that is produced by plants that have flowers (angiosperms), it's the male germinate cell, analogous to spermatozoon in animals.
All these organs are part of the reproductive system in plants, and are not present in animals. But we can make analogies to some of these structures with the animal reproductive system as we did with pollen and spermatozoon
I believe the answer is option A
D. The large surface area of leaves allows for maximum light absorption.