We can find the y-intercept by writing the slope-intercept form of the equation. For that first we need to find the slope of the given line.
![Slope=m= (17-3)/(10-6)= (7)/(2)](https://img.qammunity.org/2019/formulas/mathematics/college/58q6hscu3ubqlw1y6h137op0xp8gqnyk4q.png)
Using the slope m =7/2 and a point (6,3) we can write the equation of the line as:
![y-3= (7)/(2)(x-6) \\ \\ y= (7x)/(2)-21+3 \\ \\ y= (7x)/(2)-18](https://img.qammunity.org/2019/formulas/mathematics/college/844u7dnvvmq93zoz43rubv897ivelxns85.png)
The equation above is in the slope intercept form.Coefficient of x is the slope and constant term is the y-intercept.
So, the y-intercept for the line is -18. Therefore, option C is the correct answer