Serum differs from the blood in:

Options

A. Lacking antibodies
B. Lacking globulins
C. Lacking albumins
D. Lacking clotting factors

Explanation

To answer the question "Serum differs from the blood in:", we need to analyze the components of serum and blood and identify the key differences.

### Step-by-Step Solution:

1. **Understanding Blood Composition**: Blood is composed of various components including red blood cells, white blood cells, platelets, plasma, and clotting factors. Plasma is the liquid portion of blood that contains water, electrolytes, proteins, hormones, and waste products.

2. **Defining Serum**: Serum is the clear yellowish fluid that remains after blood has clotted. It is essentially plasma without the clotting factors. When blood clots, the clotting factors are used up in the process, and the remaining fluid is serum.

3. **Identifying Key Differences**:
- **Clotting Factors**: The most significant difference between serum and blood is that serum lacks clotting factors. Blood contains clotting factors which are essential for the coagulation process.
- **Presence of Proteins**: Serum still contains proteins such as antibodies and albumin, which are important for immune response and transport functions, respectively.

4. **Evaluating the Options**:
- **Option 1: Anti-bodies**: Incorrect, as serum contains antibodies.
- **Option 2: Lacking Globulins**: Incorrect, serum contains globulins which help fight infections.
- **Option 3: Lacking Albumin**: Incorrect, serum contains albumin which is important for transport.
- **Option 4: Lacking Clotting Factors**: Correct, serum does not contain clotting factors since they are consumed during the clotting process.

5. **Conclusion**: The correct answer to the question is that serum differs from blood in that it lacks clotting factors.