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

A. $4$

B. $3$

C. $12$

D. $2$

E. $1$

$x$ | $y$ |

3 | 14 |

5 | 22 |

6 | 26 |

7 | 30 |

A. $4$

B. $3$

C. $12$

D. $2$

E. $1$