I would choose the mountain ecosystem.
The mountain ecosystem contains a complex living organisms.
Mountain lands support a diverse array of habitats with large range of plants
and animals. It is very crucial for biological diversity and is very wonderful
to see. The climate is mostly cool which is fitting for relaxation.
D surface tension because, adhesion is sticking, b makes no sense for this question, and heat has nothing to do with it either, because it distributes it's weight throughout its legs so it doesn't sink (it doesn't weigh much so this works.)
Hope this helps don't forget to hit that heart :)