(A) : Bakelite is thermosetting polymer.
(R) : Bakelite has three dimensional network structure.

Options

A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. Both (A) and (R) are true (R) is not the correct explanation of (A)
C. (A) is true but (R) is false
D. (A) is false but (R) is true

Answer

To solve the question regarding Bakelite being a thermosetting polymer and its three-dimensional network structure, we can break it down into the following steps:

### Step 1: Understand the Assertion
The assertion states that "Bakelite is a thermosetting polymer."
- **Explanation**: Thermosetting polymers are polymers that become irreversibly hard when heated. They cannot be remolded or reshaped after they have been set.

### Step 2: Understand the Reason
The reason states that "Bakelite has a three-dimensional network structure."
- **Explanation**: Bakelite is formed through the polymerization of phenol and formaldehyde, resulting in a cross-linked structure. This three-dimensional network structure is what gives Bakelite its thermosetting properties.

### Step 3: Analyze the Relationship Between Assertion and Reason
- Both the assertion and the reason are true. The reason provides a correct explanation for why Bakelite is classified as a thermosetting polymer. The three-dimensional network structure is essential for the properties that define thermosetting polymers.

### Step 4: Choose the Correct Option
Based on the analysis:
- Both the assertion and reason are true, and the reason is the correct explanation of the assertion.

Thus, the correct answer is: **Both assertion and reason are true, and reason is the correct explanation of assertion.**

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