Final answer:
The ability of a molecule to cross the plasma membrane is dependent on its shape, chemical properties, charge, and size,. Therefore, all of the choices are correct.
Step-by-step explanation:
The ability of a molecule to cross the plasma membrane is influenced by several factors, including the molecule's shape, its chemical properties, charge, and size. Molecules that are small, nonpolar, and uncharged, such as oxygen and carbon dioxide, can pass through the membrane via simple diffusion.
On the other hand, larger, polar, or ionic molecules, or those with a charge, cannot easily cross the phospholipid bilayer due to repulsion from the hydrophobic tails of the bilayer, and may require specialized transport proteins, channels, or carriers to facilitate their passage through the membrane in a process known as facilitated transport. Therefore, the correct answer is E) all of the choices are correct, as the various chemical and physical characteristics of a molecule can influence its ability to permeate the cell membrane.