Which of the following statements is not true of the correlation r between the lengths in inches and weights in pounds of a sample of brook trout?

(a) r must take a value between −1 and 1.

(b) r is measured in inches.

(c) If longer trout tend to also be heavier, then r > 0.

(d) r would not change if we measured the lengths of the trout in centimeters instead of inches.

(e) r would not change if we measured the weights of the trout in kilograms instead of pounds.