**Core Concept:** The question is asking about a specific organism that can cause multiple alveolar-like masses in the liver. Understanding the normal liver histology, which includes hepatocytes, bile ductules, and sinusoids, is essential to answer this question correctly.

**Why the Correct Answer is Right:**
Correct Answer: **D. Schistosoma mansoni**

Schistosoma mansoni is a type of blood fluke (helminth) that infects humans, particularly in tropical regions. In the liver, Schistosoma mansoni causes an immune response that leads to the formation of granulomas around the parasites. These granulomas can lead to the development of multiple alveolar-like masses, known as hepatosplenic schistosomiasis.

**Why Each Wrong Option is Incorrect:**
A. **Schistosoma haematobium:** This is a different species of blood fluke that primarily affects the genitourinary tract, not the liver.
B. **Adenocarcinoma:** This is a type of cancer that arises from glandular cells and is not caused by a parasitic infection.
C. **Hepatitis B:** Hepatitis B is a viral infection that primarily affects the liver and can cause liver inflammation, but it does not result in alveolar-like masses.

**Why Each Wrong Option is Incorrect:**
D. **Schistosoma mansoni (Correct Answer):** As mentioned earlier, this is the organism that can cause multiple alveolar-like masses in the liver due to the formation of granulomas in response to the parasite.

**Clinical Pearl:**
Understanding the differential diagnosis of liver masses is crucial for medical professionals. In endemic areas, schistosomiasis should be considered in the list of differential diagnoses for liver masses, especially when the patient has a history of travel or residency in endemic regions.