Which of the following statements about drug distribution is true?

Drugs can cross cell membranes by passive diffusion or active transport to reach their site of action within cells or tissues. Passive diffusion occurs when drugs move from an area of high concentration to an area of low concentration, while active transport requires energy and a carrier protein to move drugs against a concentration gradient.

a. This statement is false because drugs are not distributed evenly throughout the body, but rather are distributed according to factors such as blood flow, tissue permeability, and protein binding.

c. This statement is false because while organs with high blood flow such as the liver and kidneys receive a large proportion of a drug dose, drugs can also be distributed to other organs and tissues.

d. This statement is false because some drugs can cross

Blood flow to the absorption site, surface area available for absorption, and pH at the absorption site can all affect drug absorption. For example, increased blood flow can increase drug absorption by delivering more drugs to the absorption site, while a larger surface area can increase absorption by providing more space for drug molecules to pass through. The pH at the absorption site can also affect drug absorption by altering drug solubility and ionization.