Hepatitis G / GB viruses – Identify the isolate corresponding to the hepatitis G virus lineage.

Introduction:
The term “hepatitis G virus” historically referred to viruses within the GB virus group discovered in studies of non-A–E hepatitis. Clarifying the nomenclature among GBV-A, GBV-B, and GBV-C helps avoid confusion in older literature and exam questions. This item asks which isolate corresponds to hepatitis G virus.

Given Data / Assumptions:

• GB viruses are Flaviviridae-related RNA viruses identified in the 1990s.
• Hepatitis G virus is most closely associated with GBV-C in humans.
• Other GB viruses have different host ranges or experimental relevance.

Concept / Approach:
Map historical naming: GBV-C is the human virus often labeled hepatitis G virus. GBV-B is an experimental primate virus. GBV-A designations pertain to nonhuman primates. Therefore, select GBV-C when asked to identify the agent representing hepatitis G virus in people.

Step-by-Step Solution:
Step 1: List GB viruses and their typical hosts/associations.Step 2: Link hepatitis G nomenclature to GBV-C specifically.Step 3: Exclude nonhuman primate–restricted or experimental isolates for a human-associated label.Step 4: Choose GBV-C as the correct answer.

Verification / Alternative check:
Subsequent research often refers to GBV-C as human pegivirus (HPgV). Despite evolving taxonomy, exam contexts still equate hepatitis G virus with GBV-C.

Why Other Options Are Wrong:

• GBV-B: primarily experimental hepatotropic virus in primates.
• GBA-A: not a standard designation in human hepatitis taxonomy.
• None of these/GBV-D: do not match the classic hepatitis G identification.

Common Pitfalls:
Assuming all GBVs infect humans equivalently; overlooking nomenclature updates to “pegivirus.”

Final Answer:
GBV-C (a.k.a. hepatitis G virus).