Answer: B. 65
Explanation:
Choose any point on the number line with natural numbers for both coordinates. For this case, let's use (4, 260).
To find the constant of proportionality, divide the Y coordinate by the X coordinate. 260 ÷ 4 = 65. While optional, it is reccomended to use two points to confirm your answer. Let's do that with (2, 130). Since 130 ÷ 2 = 65, this confirms that the constant of proportionality is 65.