B I think(sorry if you get this wrong)
The alveoli needs of the epithelium for the gaseous exchange and stratified squamous epithelium are formed of multiple layers the difficulty in a gaseous exchange
It is asking for one trait or characteristic that can be seen visibly and environmental traits are characteristics caused by your geographic location for example African people have more melanin in their skin because they live closer to the equator and it protects them from getting sun burnt.
The answer is B) Weathering occurs when rocks are subjected to the movement of wind and/ or water.
Explanation:
A) Cannot be A) because there’s actually 5 different types of weathering. Physical, chemical and biological.
Cannot be C) because weathering is caused by nature.
Cannot be D) because that would be Erosion.
