You can write 1000000 is 10 times as many then 100000
The answer would be D) The union of two nations who have a common purpose.
If you plot all the points, you'll see that they lie on the same straight line. Therefore the function is not exponential.
In terms of the context of your answer choices, the final answer is choice A. The domain values are at regular intervals (in this case 2) while the range values increment by the same value as well (1 in this case).
10 years makes up one decade, hope this helps!