**Core Concept**
Ritonavir is a protease inhibitor used in the treatment of HIV/AIDS. It works by inhibiting the protease enzyme, which is essential for the replication of the virus. Ritonavir is also known for its potent pharmacokinetic boosting effect, which enhances the absorption of other protease inhibitors.

**Why the Correct Answer is Right**
Ritonavir interacts with various other medications, including terfenadine, a non-sedating antihistamine. This interaction can lead to increased levels of terfenadine, which can cause QT interval prolongation and potentially life-threatening arrhythmias. Ritonavir can cause gastrointestinal symptoms such as nausea, vomiting, and diarrhea due to its inhibitory effect on the gastrointestinal motility. Ritonavir is metabolized by the liver and excreted in the bile, and its use is not contraindicated in renal failure. However, patients with renal impairment may require dose adjustments. Ritonavir is a protease inhibitor, not a non-nucleoside reverse transcriptase inhibitor (NNRTI). NNRTIs, such as efavirenz and nevirapine, work by binding to the reverse transcriptase enzyme and inhibiting its activity.

**Why Each Wrong Option is Incorrect**
**Option B:** G.I. symptoms are seen, which is true, but it's not the only correct statement.
**Option C:** Contraindicated in renal failure, which is incorrect as it's not a contraindication.
**Option D:** It is NNRTI, which is incorrect as it's a protease inhibitor.
**Option E:** Should not be used in AIDS patient with bleeding disorder, which is incorrect as there's no direct contraindication.

**Clinical Pearl / High-Yield Fact**
Ritonavir's potent pharmacokinetic boosting effect makes it a crucial component of many antiretroviral regimens. However, its use requires careful monitoring of drug interactions and potential side effects.

**Correct Answer: B. G.I. symptoms are seen**