What is the principle of superposition? A. The layers of sediment on the bottom are the oldest. B. All layers of sediment are identical. C. In a given region, all layers of sediment form at the same time. D. The geologic processes of today are very different from those in the past.

Supperposition = the oldest layer in a sequence of undisturbed sedimentary rock is on the bottom

endo:

regulates body hormones, aldosterone, vasopressin

neural:

signal, regulates body using electric signals, reflex

endo has to do with hormones; aldosterone and vasopressin are both hormones. i also had this question and got it right : d