**Core Concept**
Hepatitis B infection is a complex liver disease caused by the hepatitis B virus (HBV), which can lead to chronic infection, liver cirrhosis, and hepatocellular carcinoma. The virus has distinct attributes that differentiate it from other forms of hepatitis.

**Why the Correct Answer is Right**
HBcAg (hepatitis B core antigen) is not typically found in the serum of individuals with active hepatitis B infection. Instead, the presence of HBcAg is usually indicative of a past or resolved infection. The presence of HBcAg in the serum is a result of the breakdown of HBV-infected hepatocytes, which release HBcAg into the bloodstream. This is an important distinction because the absence of HBcAg in the serum does not rule out active infection.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is correct. Hepatitis B infection established in infants can indeed lead to chronic infection, as the virus is able to evade the infant's immune system and establish a lifelong infection.
**Option C:** This statement is also correct. Chronic hepatitis B infection is a known risk factor for the development of hepatocellular carcinoma, a type of liver cancer.
**Option D:** This statement is correct as well. Alpha interferon is a treatment option for chronic hepatitis B infection, particularly in cases where the infection is resistant to antiviral medications.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the presence of HBcAg in the serum is not a reliable indicator of active hepatitis B infection. Instead, the presence of HBsAg (hepatitis B surface antigen) in the serum is a more reliable indicator of active infection.

**✓ Correct Answer: B. HBcAg in serum indicate active infection**