Which would most likely pass unaided through a plasma membrane?

Question

Quizplus · Accepted Answer

Something small and nonpolar, like nitrogen gas, can pass unaided through a plasma membrane because it can diffuse through the hydrophobic tails of the phospholipid bilayer.

Answer: D
 Something large, like a glucose molecule, cannot pass unaided through a plasma membrane because it cannot diffuse through the hydrophobic tails of the phospholipid bilayer. It requires a transport protein to facilitate its movement across the membrane.

Which Would Most Likely Pass Unaided Through a Plasma Membrane