Dengue fever can be thrombocytopenia due to direct infection of 

Options

A. Thrombocytes
B. Bone marrow megakaryocytes
C. Lymphocytes
D. WBC

Answer

To solve the question regarding the cause of thrombocytopenia in dengue fever, we can follow these steps:

### Step 1: Understand the Components of Blood
Blood consists of various components, primarily red blood cells (RBCs), white blood cells (WBCs), and platelets (thrombocytes). Each of these components has a specific function and origin.

### Step 2: Identify the Role of Platelets
Platelets, also known as thrombocytes, are crucial for blood clotting. They are not whole cells but rather fragments derived from larger cells in the bone marrow called megakaryocytes.

### Step 3: Recognize the Impact of Dengue Fever
Dengue fever is known to cause thrombocytopenia, which is a condition characterized by a low platelet count. This can lead to increased bleeding and other complications.

### Step 4: Determine the Source of Thrombocytopenia in Dengue
The decrease in platelet count during dengue fever is primarily due to the infection of megakaryocytes in the bone marrow. Since megakaryocytes are responsible for producing platelets, their infection leads to a reduced production of platelets.

### Step 5: Analyze the Options Given
- **Thrombocytes**: Incorrect, as they are the end product and not directly infected.
- **Bone marrow**: Partially correct, but it’s more specific to megakaryocytes.
- **Megakaryocytes**: Correct, as they are directly infected by the dengue virus.
- **Lymphocytes and WBCs**: Incorrect, as they are not directly involved in platelet production.

### Conclusion
The correct answer to the question is that dengue fever causes thrombocytopenia due to the direct infection of **megakaryocytes** in the bone marrow.

---