Heyy there.
I'm thinking that it would be B. or D. but idk exactly which one it is.
I hope you figure out wat it is.
B. Thinnest under the oceans and thickest under continents
D. Least dense layer overall, consists of two layers of different thickness
Good Luck and enjoy the rest of ur day!! ^^
Add starch indicator solution to the water in the beaker. If the indicator solution changes color than starch is present.