Which of the following describe the quantities that are proportional to one another.
a. The gallons of water in a tub and the number of seconds since the tap was opened.
B. The height of a ball and the number of minutes since it was thrown.
C. The length of a side of a square and the perimeter of the square.
D. The length of a side of a quart and the area of the square.
E. There temperature outside dropping at 3 degrees per hour and the number of hours since noon, when it was 0 degrees.
