**Core Concept**
The incubation period of Hepatitis B refers to the time between exposure to the Hepatitis B virus (HBV) and the onset of symptoms. This period is crucial in understanding the disease's progression and the potential for transmission. The incubation period of HBV varies among individuals, but it typically ranges from 45 to 180 days.

**Why the Correct Answer is Right**
The incubation period of HBV is influenced by factors such as the viral load, the route of transmission, and the individual's immune response. During this period, the virus replicates in the liver, leading to inflammation and liver damage. The correct answer represents the average incubation period of HBV, which is approximately 90 days. This duration allows the virus to establish a chronic infection in some individuals, leading to long-term liver damage and potential progression to cirrhosis or hepatocellular carcinoma.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the incubation period of HBV is not typically less than 30 days. Such a short incubation period would not allow sufficient time for the virus to replicate and cause significant liver damage.
**Option B:** This option is incorrect because the incubation period of HBV is not typically longer than 180 days. While some individuals may experience a longer incubation period, this option is too broad and does not accurately represent the average duration.
**Option C:** This option is incorrect because the incubation period of HBV is not typically as short as 5 days. Such a short incubation period would not allow sufficient time for the virus to replicate and cause significant liver damage.

**Clinical Pearl / High-Yield Fact**
The Hepatitis B virus can remain in the body for up to 6 months after the incubation period, even if symptoms have resolved. This prolonged viral shedding increases the risk of transmission to others, highlighting the importance of proper infection control measures and vaccination.

**Correct Answer: C. 90 days**