Answer:
A.
Step-by-step explanation:
In a Linear Function, the changes between x and y should remain constant.
A: x increases by 2 while y increases by 2 steadily so it is a linear function.
B: x increases by 1 and then zooms up to increasing in double (2) while y increases by 2 and then zooms up to increasing to more than double (5) so B is not a linear function.
C: x increases by 3, then one-third of 3 (1), then two-third of 3 (2). y decreases by 6, then one-third of 6 (2), then one-third (2) again when it should have decreased by two-third of 6 (4). Notice that the last decrease was different from x.
D: x increases by 6, then one-third of 6 (2), then half of 6 (3). y decreases by 3, then one-third of 3 (1), then two-third of 3 (2) when it should have decreased by half of 3 (1.5). Notice the last decrease was different from x.
