The answer is; C
Intravenous (IV) drugs are directly injected into the bloodstream to achieve a rapid medical response by the body. It is extremely critical that the needle used in the injection is sterile because the introduction of foreign material into the blood through the injection can result in the most serious infection. This is because using injections breaches the first line of the immune defenses which is the innate immune response of the skin by directly introducing disease-causing organisms into the blood.