Why Do Some Hormones, Like Thyroxin, Affect Most or All

Multiple Choice

Why do some hormones, like thyroxin, affect most or all body cells while others only affect a single organ or type of cell?

A) Because of variations in hormone concentration-when present in high concentration a hormone can stimulate a greater number of body locations.
B) Because of variations in receptor distribution-all cells or organs with receptors for the hormone will be affected.
C) Because of variations in membrane permeability-hydrophobic hormones enter and affect all cells, whereas hydrophilic hormones have more limited affects.
D) Because of variations in signal transduction-only cells with the appropriate enzymes needed to activate the hormone will respond to its signal.