What is probability? ​

probability is a concept which numerically measures the degree of certainly of the occurrence of events.

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain

an economic reason that the south needed a reconstruction plan is that plantations, factories, and other businesses were destroyed during the war.