Since World War II, the economy of Saudi Arabia has been based primarily on .

Select the best answer from the choices provided.
A. agriculture
B. the annual Muslim pilgrimage to Mecca
C. craft industry
D. oil revenue

Explanation:

the answer is oil revenue

please mark me un brainlist

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.  

it refers to race, i am pretty sure this was a popular term in nazi germany or something.