Answer: A. escarpment
Step-by-step explanation:
To find our answer, we can look at the definitions, all from Oxford Languages, of the other words given:
A. escarpment = "long, steep slope, especially one at the edge of a plateau or separating areas of land at different heights."
B. macumba = "a folk religion practiced by some people in Brazil, combining elements of Brazilian Roman Catholicism and spiritualism with traditional African religious practices."
C. reservoir = "a large natural or artificial lake used as a source of water supply."
D. rain shadow = "a region having little rainfall because it is sheltered from prevailing rain-bearing winds by a range of hills."
The only word that makes sense in this context is the first;
A. escarpment
A steep cliff or slope between a higher and lower land surface is an escarpment.