Using the graph below, what can you infer about the correlation of us crude oil production and imports between 1920 and 2020?

a). after 1980, as the us crude oil production decreases, the amount of imports remains stable.

b). until 1980, as us crude oil production increased, the amount of imports increased.

c). before 1980 as the us crude oil production increases, the amount of imports decreases.

d). there are no correlations between us crude oil and imports.