Consider following figure `A` and `B` indicating distribution of charge density `("electron probability" Psi^(2))` with distance `r`.
Select the correct statement:
A. `A` and `B` both for `1s`
B. `A` and `B` both are for `2s`
C. `A` is for `2s`, `B` is for `1s`
D. `A` is for `1s`, `B` is for `2s`