A 19-year-old presents with abdominal pain in the right lower quadrant. Physical examination reveals rebound tenderness and a low-grade fever. A possible diagnosis would be:

Choice A reason:
Viruses are known for their unique replication process. They cannot replicate independently and must hijack a host cell's machinery to reproduce. This characteristic is fundamental to understanding viruses and is a key concept in virology. By replicating their genetic material inside host cells, viruses ensure their propagation and survival. This answer is correct because it highlights this crucial aspect of viral biology.
Choice B reason:
This choice is incorrect because viruses are not easily killed by antimicrobials. Antimicrobials, such as antibiotics, are typically effective against bacteria, not viruses. Viruses have different structures and replication mechanisms that make them resistant to these treatments. Instead, antiviral medications are needed to target viruses specifically.
Choice C reason:
This choice is also incorrect. Viruses do contain either DNA or RNA as their genetic material. This genetic material is essential for their replication and propagation. Some viruses have DNA, while others have RNA, and this distinction is one of the primary ways viruses are classified.
Choice D reason:
Viruses are not capable of independent reproduction. They rely entirely on infecting host cells to replicate. This dependence on host cells distinguishes them from other microorganisms like bacteria, which can reproduce on their own. Thus, this choice is incorrect as it does not accurately reflect the nature of viruses.

Choice A reason:
Pulmonary embolism is not a typical complication of a peptic ulcer. While serious, pulmonary embolism is unrelated to the gastrointestinal tract and would not arise from ulceration of the stomach or duodenum. It is therefore not the correct answer to the question posed.
Choice B reason:
Bleeding is the primary clinical manifestation of greatest concern with a peptic ulcer. Ulcers can erode into blood vessels, leading to gastrointestinal hemorrhage, which may present as hematemesis (vomiting blood) or melena (black, tarry stools). Severe bleeding can result in hypovolemic shock and requires immediate medical intervention, such as endoscopic hemostasis, blood transfusions, or surgery. This makes bleeding the most critical concern among the options listed.
Choice C reason:
Bowel obstruction can occur as a complication of peptic ulcer disease but is less common compared to bleeding. It arises from scarring or swelling near the pylorus, leading to gastric outlet obstruction. While serious, it is not the most frequent or immediate concern in the context of peptic ulcers.
Choice D reason:
Hepatomegaly, or enlargement of the liver, is unrelated to peptic ulcer disease. This symptom is typically associated with liver conditions such as cirrhosis, hepatitis, or cancer, and does not result from ulcer pathology.