Hint: It is a layer found in the living cells of the endosperm and its particular presence is what you need to crack. It helps in embryo protection and storage of food.
First of all, you should know what an Aleurone layer is. Aleurone layer is a layer in the living cells of endosperm which encloses the outer surface of the endosperms of the cereal grains. It performs an important digestion function during the time of germination i.e., it secretes hydrolases enzymes which break down starch and proteins present in the endosperm cells. This helps in embryo protection, storage of food and the utilisation of stored food too.
> Option A which is the outer layer of scutellum in contact with endosperm, this option is not correct as the aleurone layer is not the outer layer of scutellum as this layer encloses the outer surface of endosperms of cereal grains.
> Option B which is a layer of pericarp specialized in absorption of water. It is also not the correct one since the aleurone layer is not the pericarp layer and it does not perform absorption of water.
> Option C which is Layer present in the hypocotyl that guides pollen tube, this layer is not present in the hypocotyl too. Hence, this is not the correct option.
> Option is D which is Layer present on the outside of endosperm with protein grains, this option is the correct one as aleurone layer is the layer which is present in the cells of endosperm which encloses the outer surface of the endosperm of the cereal grains or with the protein grains. Hence, this option is the correct one.
Hence, The correct answer is option (D).
Note: Aleurone layer is a protein found in proteins granules of the seeds which are maturing. From the given explanation, you can crack this question or you should know what aleurone layer is and where it is found you can easily find the correct option.