Answer:
<h2>The function is a direct variation function with a constant of variation of 1.5.</h2>
Step-by-step explanation:
A direct variation function can be seen has a linear function, which has a proportional relationship between variables, which ratio is the slope of the line.
If we see all three points, the increases a constant number.
10,14,18: here you can see that x-variable is increasing constantly by 4.
18, 24, 30: here you can see that y-variable is increasing constantly by 6.
So, if we use to points and the definition of slope, we have:

Therefore, <em>the ratio of change or the constant of variation is 1.5.</em>
So, the right answer is the first one.