One great advantage that came with moving out West to the prairies to farm is that there is something absent on the prairies. What is the missing part that made farming easier

Forests

Explanation:The missing part that made farming easier was the availability of Forests which was not available on the Prairies.

The trees' plantation is the missing part of prairies that made farming easier

Explanation:

Prairies are enormous stretches of flat grassland with moderate temperatures, moderate rainfall, and few or absence of trees.

In a grassland, trees do not growth. This made cultivation of plants such as wheat, millet, or some other crops easier.

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

the fact that could also be added to column b is that during world war ii, specifically between the years 1941 and 1945, japan expanded its territory towards the indonesian territory in what was known later as part of the "pacific war". in that time, japan could conquer the philipines, singapore,   borneo, central java, malang, cebu, sumatra and various other islands of the area, therefore expanding its territory for a brief period of time.