Assertion (A) Bond angle is ethers is slightly less than tetrahedral angle.
Reason (R) There is a repulsion between the two bulky (-R) groups.

Options

A. Assertion and reason both are correct and reason is correct explanation of assertion.
B. Assertion and reason both are wrong statements.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement.

Explanation

To analyze the given question regarding the assertion and reason about the bond angle in ethers, we can break it down step by step:

### Step 1: Understand the Assertion
The assertion states that "the bond angle in ethers is slightly less than the tetrahedral angle." The tetrahedral bond angle is approximately 109.5 degrees.

**Hint:** Recall the typical bond angles associated with different molecular geometries, especially tetrahedral geometry.

### Step 2: Evaluate the Bond Angle in Ethers
In ethers, the bond angle is influenced by the presence of two bulky alkyl (R) groups. Due to the repulsion between these bulky groups, the bond angle in ethers is actually slightly greater than the tetrahedral angle. The typical bond angle in ethers is around 111.7 degrees.

**Hint:** Consider how the size and electron cloud of the R groups can influence the bond angles.

### Step 3: Analyze the Reason
The reason provided states that "there is a repulsion between the two bulky (-R) groups." This statement is true because the larger the groups attached to the central atom, the more they will repel each other due to their electron clouds.

**Hint:** Think about how molecular geometry and steric effects can lead to variations in bond angles.

### Step 4: Conclusion on Assertion and Reason
Since the assertion is incorrect (the bond angle in ethers is greater than the tetrahedral angle), but the reason is correct (there is repulsion between the bulky R groups), we conclude that the correct answer is that the assertion is wrong, but the reason is correct.

**Hint:** Remember the distinction between the correctness of the assertion and the reason when evaluating their relationship.

### Final Answer
The assertion is incorrect, while the reason is correct. Therefore, the correct option is D: Assertion is wrong but Reason is correct.