The following table shows $\left(x, \; y\right)$ values for a linear function. What is the slope of this function?
A. $2$
B. $3$
C. $6$
D. $9$
E. $1$
| $x$ | $y$ |
| 3 | 9 |
| 5 | 13 |
| 9 | 21 |
| 10 | 23 |
A. $2$
B. $3$
C. $6$
D. $9$
E. $1$
