[A]: Amino acids are converted into ammonia by a group bacteria called ammonifying bacteria.
[R]: The majority of plants, however, can not utilize ammonium compounds as a source of nitrogen

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

To solve the question regarding the assertion (A) and reason (R), we need to analyze both statements carefully.

### Step-by-Step Solution:

1. **Understanding Assertion (A)**:
- The assertion states that "Amino acids are converted into ammonia by a group of bacteria called ammonifying bacteria."
- This statement is true because ammonifying bacteria play a crucial role in the nitrogen cycle by breaking down organic matter, including amino acids, into ammonia through the process of ammonification.

2. **Understanding Reason (R)**:
- The reason states that "The majority of plants, however, cannot utilize ammonium compounds as a source of nitrogen."
- This statement is partially true. While it is correct that some plants cannot utilize ammonium directly, many plants can actually use ammonium as a nitrogen source. Therefore, this statement is misleading as it generalizes the ability of all plants.

3. **Evaluating the Relationship**:
- The assertion (A) is true, but the reason (R) does not correctly explain the assertion. The assertion talks about the conversion of amino acids to ammonia, while the reason discusses the utilization of ammonium by plants, which is not a direct explanation for the process described in the assertion.

4. **Conclusion**:
- Based on the analysis, we can conclude that both A and R are true, but R is not a correct explanation of A.

### Final Answer:
Both A and R are true, but R is not a correct explanation of A.

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