Where is human settlement best supported?

a: oasis

b: rocky plateau

c: salt-crusted flat

d: gravel-covered plain

An Oasis because a gravel-covered plain would hurt there feet. A salted crusted flat is dangers if one little piece of water touches the salt could ruin the whole area. A rocky plateau they would have have to climb up and down the plateau and they could get hurt. A Oasis has pure water, and enough trees to keep most or all the air pure, and almost to no dangers animals