The following table shows $\left(x, \; y\right)$ values for a linear function. What is the slope of this function?

A. $3$

B. $2$

C. $6$

D. $4$

E. $1$

$x$ | $y$ |

2 | 8 |

6 | 20 |

9 | 29 |

11 | 35 |

A. $3$

B. $2$

C. $6$

D. $4$

E. $1$