Biology Question:. .
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.Which one of these scenarios most likely uses facilitated transport to move molecules across the cell membrane?
A) Oxygen moves from high to low concentration across the phospholipid bilayer.
B) K+ moves from low to high concentration using a membrane protein.
C) Glucose moves with the concentration gradient from high to low concentration using a membrane protein.
D) Ca+2 ions move against the concentration gradient through a gated channel to initiate an action potential.