What is the rule for the function shown in the table?
x -1 0 1 2
y -2 1 4 7
A. y = 1/3 x + 1
B. y = 3 x + 1
C. y = 1/3 x
D. y = 1/2 x + 1
x -1 0 1 2
y -2 1 4 7
A. y = 1/3 x + 1
B. y = 3 x + 1
C. y = 1/3 x
D. y = 1/2 x + 1