Ram's blood cells do not agglutinate with addition of either anti-A or anti-B serum. However, serum collected from Ram causes agglutination of RCBs collected from another person.
Based on the above information, blood group of Ram is most likely.

Options

A. A
B. B
C. O
D. AB

Answer

To determine Ram's blood group based on the information provided, we can follow these steps:

### Step 1: Understand the Blood Group System
The ABO blood group system is determined by the presence of antigens (A and B) on the surface of red blood cells (RBCs) and the presence of antibodies in the serum. The possible blood groups are A, B, AB, and O.

### Step 2: Analyze Ram's RBCs
The question states that Ram's blood cells do not agglutinate with either anti-A or anti-B serum. This indicates that there are no A or B antigens present on Ram's RBCs. Therefore, Ram cannot have blood groups A, B, or AB, as those groups would have either A or B antigens.

### Step 3: Analyze Ram's Serum
The question also mentions that serum collected from Ram causes agglutination of RBCs from another person. This means that Ram's serum contains antibodies that react with antigens present on the RBCs of the other person. Since Ram's RBCs do not have A or B antigens, it is likely that his serum contains both anti-A and anti-B antibodies.

### Step 4: Determine Ram's Blood Group
Given that Ram's RBCs lack A and B antigens, and his serum contains both anti-A and anti-B antibodies, we can conclude that Ram's blood group is O. In blood group O, there are no antigens on the RBCs, and both anti-A and anti-B antibodies are present in the serum.

### Conclusion
Based on the analysis, Ram's blood group is most likely **O**.

### Final Answer
**Option C: O**

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