Type i alveolar cells:
a. secrete surfactant.
b. are squamous epithelial cells.
c. are macrophages.
d. function mainly in the diffusion of gases.
e. both b and d.

The correct option is: e. Both B and D

Explanation:

Type I alveolar cells are the thin squamous epithelial cells that lines the alveolar surface of the pulmonary alveoli.

These cells are involved in the gas exchange process. The thin lining of the type I alveolar cells, allows the rapid diffusion of gas and thus enabling the exchange of gases between the blood present in the capillaries and the air present in the pulmonary alveoli.

what's the rest of the question

1. law of superposition: when there are horizontal layers of rock. the layers at the top are the youngest.

2. law of uncomformity: where one layer is much younger than the previous one, therefore creating a gap in the time record.

3. inclusion: when there is a solid stone inside of another.

4. intrusion: a feature formed when a stone is filled with magma.

hope i answered your question.