I really need help on this! The Missouri River played an important role in westward expansion as the jumping off point (a beginning from which an enterprise is launched) for the , which opened up the American west.

A:California Trail
B:Oregon Trail
C:Santa Fe Trail
D:All of the Above

I think the answer is D not sure tho

All of the above!!

step by step explanation

The constant presence of diseases or infectious agents within a given geographic area or population group. it may also refer to the usual prevalence of a given disease with such area or group. it includes holoendemic and hyperendemic diseases. a holoendemic disease is one for which a high prevalent level of infection begins early in life and affects most of the child population, leading to a state of equilibrium such that the adult population shows evidence of the disease much less commonly than do children (malaria in many communities is a holoendemic disease). a hyperendemic disease is one that is constantly present at a high incidence and/or prevalence rate and affects all groups equally. so probably family history.