Which of the following routes is affected by the first-pass effect?

A. The first-pass effect refers to the metabolism of a drug in the liver before it reaches systemic circulation. This primarily affects oral medications, as they are absorbed through the gastrointestinal tract and first pass through the liver. B. Intravenous (IV) drugs bypass the first-pass effect as they are directly introduced into the bloodstream. C. Intramuscular (IM) and D. Subcutaneous (SC) routes also bypass the first-pass effect since the drug enters the bloodstream without passing through the liver initially.