## Core Concept
The question pertains to the serological markers and clinical features observed in a patient with active chronic hepatitis B. Hepatitis B virus (HBV) infection can lead to various clinical manifestations, ranging from acute to chronic infection. Chronic hepatitis B is characterized by the persistence of HBV infection for more than six months, leading to inflammation and damage to the liver.

## Why the Correct Answer is Right
In active chronic hepatitis B, patients typically exhibit certain serological markers and clinical features. The hepatitis B e-antigen (HBeAg) and hepatitis B surface antigen (HBsAg) are commonly found in the serum of patients with active viral replication. The presence of HBeAg usually indicates viral replication and high infectivity. On the other hand, the antibody to hepatitis B e-antigen (anti-HBe) often signifies a less active phase of the disease or a response to antiviral therapy.

## Why Each Wrong Option is Incorrect
- **Option A:** HBsAg is a marker of current HBV infection and is expected to be present in a patient with chronic hepatitis B.
- **Option B:** HBeAg positivity indicates active viral replication, which is common in active chronic hepatitis B.
- **Option D:** Anti-HBc (antibody to hepatitis B core antigen) is also expected as it appears during the acute phase of infection and persists in chronic infection.

## Why Option C is Correct (Implicitly)
- **Option C:** Anti-HBs (antibody to hepatitis B surface antigen) typically indicates immunity to HBV, either from vaccination or past infection. In the context of active chronic hepatitis B, the presence of anti-HBs is not typical unless the patient is in a rare phase of chronic infection known as "surface antigen-negative" or "occult" HBV infection, or has been treated and achieved a response. However, in the context of "active" chronic hepatitis B with viral replication, one would not expect to see anti-HBs alongside HBeAg and HBsAg.

## Clinical Pearl / High-Yield Fact
A key point to remember is that in chronic hepatitis B, the presence of HBeAg and HBsAg with or without anti-HBc IgM is indicative of active viral replication. The absence of anti-HBs (or its presence in very low levels) in the setting of active disease helps differentiate it from a resolved infection or successful vaccination.

## Correct Answer: C. anti-HBs