Answer:
The correct option is d.
Explanation:
From the graph it is noticed that the line passing through origin and point A. The coordinates of point A is (5,35).
The coordinates of origin is (0,0).
Slope formula,

Slope of the line is,

Therefore, the amount of water increase 7 liters per minute. So the option A is incorrect.
Point A is not the origin therefore the option b is incorrect.
The x-axis represent the time and the y-axis represents the water in liters therefore the point A(5,35) represents 35 liters of water at 5 minutes. So the option c is incorrect.
Since the line graph passes through the origin therefore the x and y has proportional relationship. Therefore the option d is correct.