An Infomercial Advertising an Amazing New Weight-Loss Product Claims That

An infomercial advertising an amazing new weight-loss product claims that the powder "increases your metabolism." Which of the following would provide the strongest support for this hypothesis?

A) Evidence that T₄ levels remain constant within groups using the product but vary in the control groups
B) Evidence that thyroxine levels rise in people using the product
C) Evidence that the product increases the density of steroid receptors in the brain
D) Claims made by a professional athlete that the product led to weight loss
E) Evidence that activity in the posterior pituitary increases in people using the product