Which function rule represents the data in the table below?

X | 1 | 2 | 3 | 4 | 5
Y | 9 | 12| 15 | 18 | 21

A: y=4+5x
B: y=3+6x
C: y=5+4x
D: y=6+3x

C: y=5+4x

To determine which function rule represents the data in the table, we need to analyze the relationship between the values of x and y.

Looking at the table, we can see that when x increases by 1, y increases by 3. This means that the rate of change between x and y is constant, which suggests a linear function.

Now let's look at each option:

A: y=4+5x
With this function, when x=1, y=9, and when x=2, y=14. This does not match the values in the table, so option A is not correct.

B: y=3+6x
With this function, when x=1, y=9, and when x=2, y=15. This does not match the values in the table, so option B is not correct.

C: y=5+4x
With this function, when x=1, y=9, and when x=2, y=13. This does not match the values in the table, so option C is not correct.

D: y=6+3x
With this function, when x=1, y=9, and when x=2, y=12. This matches the values in the table.

Therefore, the correct function rule that represents the data in the table is D: y=6+3x.