(A) : Among IIIA group elements, Boron has highest melting point
(R) : Boron has gaint polymeric structure

Options

A. A and R are true, R explains A
B. A and R are true, R does not explain A
C. A is true, but R is false
D. A is false, but R is true

Answer

To solve the question regarding the assertion and reason about boron and its melting point, we can break it down step by step:

### Step 1: Understand the Assertion
The assertion states that "Among IIIA group elements, Boron has the highest melting point."
- **Analysis**: Boron is indeed known to have a very high melting point compared to other elements in group IIIA (such as aluminum, gallium, indium, and thallium).

### Step 2: Understand the Reason
The reason states that "Boron has a giant polymeric structure."
- **Analysis**: Boron does not have a giant polymeric structure. Instead, it has a complex crystalline structure that consists of strong covalent bonds.

### Step 3: Evaluate the Truth of the Statements
- The assertion is true: Boron has the highest melting point among the group IIIA elements.
- The reason is false: Boron does not have a giant polymeric structure.

### Step 4: Conclusion
Based on the evaluation:
- The assertion is true, but the reason is false. Therefore, the correct answer is that the assertion is true, but the reason does not explain the assertion.

### Final Answer
- A is true, but R is false.

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