Q. Competition for food, light and space is most severe in ?

Answer of this question "Competition for food, light and space is most severe in ?", here are 4 choices for this question : distantly related species growing in the same habitats , distantly related species growing in different habitats , closely related species growing in the same area on in the same niche, closely related species growing in different habitats.
Answer Is "closely related species growing in the same area on in the same niche".