Answer:
The correct answer is D) They are too charged or polar to move through the phospholipids directly.
Step-by-step explanation:
Plasma membrane is only permeable to non polar hydrophobic compounds such as oxygen,carbon dioxide lipids.steroid hormone etc.
But the plasma membranedoes not allow the charged or polar molecules to move across the phospholipid bilayer.
Facilitated diffusion helps in the transport of polar molecules such as glucose and water to pass through the lipid bilayer of the plasma membrane.To do the same facilitated diffusion takes help of 2 proteins.Among them one is carrier protein example glucose transporter and the other is channel protein example aquaporin.