Constant is the scale term in proportionality. Suppose one variable is dependent on the other and one variable become twice, other becomes also twice and if one becomes half, other too becomes half., but they are two different variables which are no-where linked (like cost(money) vs quantity). Quantity and cost are two different things but they abridge a mathematical relation of proportionality. So in the mathematics to abridge these two different variables, we need something. Constant serves that purpose.
Answer:
C
Step-by-step explanation:
Since the graph hits 0 at x = 0, your y intercept is 0.
The graph is decreasing which means you have a negative slope.
They gave you a coordinate so use it to find the slope.

That's your slope.
C is the correct answer.
1 feet = 0.3048 meters
So we do a unit conversion to cancel out the feet unit.
Look at my picture to see the work
Please let me know if this helped!
B. If (x = 5)
Hope this helped :)