The 1622 janissary revolt against the ottoman leadership was one of the situations that marked the beginning of the empire’s decline.
a. true
b. false

False.  It began when weak sultans assumed throne. Apart from this the West were able to find new trade routes where they didn’t have to pass through routes controlled by the Ottoman Turks.  Apart from that victories at Lepanto and Malta help turn the tide against the Turks.  Later on the decline of the empire led to the rebellion of the Janissaries led to its abolition.

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