Which of the Following Statements Is TRUE

Multiple Choice

Which of the following statements is TRUE?

A) Extracellular signal molecules that are hydrophilic must bind to a cell-surface receptor so as to signal a target cell to change its behavior.
B) To function, all extracellular signal molecules must be transported by their receptor across the plasma membrane into the cytosol.
C) A cell-surface receptor capable of binding only one type of signal molecule can mediate only one kind of cell response.
D) Any foreign substance that binds to a receptor for a normal signal molecule will always induce the same response that is produced by that signal molecule on the same cell type.