Which of the statements correctly describes why ions are unable to cross the plasma membrane without channel proteins?

Explanation

The plasma membrane is made up of a phospholipid bilayer, which is a double layer of phospholipids. Phospholipids have a hydrophilic head and a hydrophobic tail. The hydrophilic heads face the outside and inside of the cell, while the hydrophobic tails face each other. The hydrophobic tails of the lipid bilayer create a barrier that prevents ions from crossing the plasma membrane. Ions are charged particles, and they are attracted to water. The hydrophobic tails of the lipid bilayer are repelled by water, so ions cannot cross through them. Channel proteins are proteins that span the plasma membrane and create pores through which ions can pass. Channel proteins are selective, so they only allow certain types of ions to pass through.