As Thomas's income rose over the last 20 years so has his stress level.
Select one:
A.
Positive correlation; direct cause
B.
Negative correlation; common underlying cause
C.
Positive correlation; common underlying cause
D.
Positive correlation; coincidence
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When gasoline prices fall, the number of cars on the freeways increases.
Select one:
A.
Negative correlation; direct cause
B.
Positive correlation; direct cause
C.
Positive correlation; common underlying cause
D.
Negative correlation; common underlying cause
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Number of appliances sold and revenue of appliance store