What geographical feature was located to the north of the West African kingdoms? a. The rainforests
b. the savanna grasslands
c. the river Niger
d. The Sahara Desert

I would say The Sahara Desert

Explanation:

The region of West Africa includes the southern portion of the bulge of the continent, which extends westward to the Atlantic Ocean. This region is bisected by the African Transition Zone, which borders the southern edge of the Sahara Desert. The main physical features include the Sahara Desert and the Niger River.

in the 1800s, locomotives powered by steam made transportation faster and cheaper. the resulting rapid growth of railroads led to the connection of the atlantic and pacific railroad in oklahoma city in 1897.

in the last years of the century, the improvement of steam-based engines the expansion and growth of railroads. this growth increased when the companies started to build and expand, such as the atlantic and pacific railroad, which connected new mexico with california, and missouri with oklahoma. many of these new networks were built in oklahoma, and these changes transportation henceforward.

the answer here would be