Vestigial because they don't use it but it's still there
The process of when a lake freezes in the winter and thaws in the spring without changing the size or shape is neither constructive or destructive! It's neither.
Answer:
The correct answer will be option-D
Explanation:
Pulmonary Surfactant is a complex substance produced by the pneumocytes epithelial II cells in the alveolar sac.
The surfactant is composed of the proteins and lipids which plays a role in keeping alveoli open by reducing the surface tension formed between the air and liquid.
The surfactant act by forming a monolayer surface film which helps reduce the surface tension.
Thus, option-D is the correct answer.
"Founder effect" is the one factor among the choices given in the question that is responsible for this phenomenon. The correct option among all the options that are given in the question is the second option or option "B". I hope that this is the answer that has actually come to your great help.
