please answer b and c with proper explanation using proper terminology

Nicotine is a highly addictive alkaloid compound found in tobacco leaves. Nicotine is also the active ingredient in NRT (nicotine replacement therapy) products, which may be used to help smokers overcome their addiction. Nicotine is absorbed into the body by direct diffusion through cell membranes. Since nicotine is a weak base, its absorption depends on pH. a. Draw the ionization equilibria of nicotine, from the fully protonated to the fully deprotonated form. (1) b. Which two forms of nicotine are predominant at the physiological pH of 7.4 ? (1) c. Which form of nicotine would be most easily absorbed into the body? Explain your choice. (2)