Consider following compounds,
(i) `H_(3)X-HCS` (ii)`H_(3)Y-NCS` (iii)`(H_(3)Y)_(2)O` (iv)`(H_(2)X)_(2)O`
The incorrect statement regarding given compounds is :

Options

A. If Y is carbon in compounds (ii) and (iii), then both are bent
B. If X is silicon in compounds (i) and (iv), then both are linear
C. If X is carbon and Y is silicon, the compound (i) is more basic than compound (ii)
D. If X is silicon and Y is carbon, then X-O-X bond angle compounds (iii) is greater than Y-O-Y bond angle in compounds (iv)

Explanation

To solve the question regarding the incorrect statement about the given compounds, we will analyze each compound and the statements provided.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- (i) `H3X-NCS`
- (ii) `H3Y-NCS`
- (iii) `(H3Y)2O`
- (iv) `(H2X)2O`

2. **Analyze the Statements**:
- We need to evaluate the statements regarding these compounds, particularly focusing on the elements X and Y in the compounds.

3. **Assume Values for X and Y**:
- Let's assume:
- If Y is Carbon (C), then:
- Compound (ii) becomes `CH3-NCS` (Methyl isothiocyanate).
- Compound (iii) becomes `C2H6O` (Dimethyl ether).
- If X is Silicon (Si), then:
- Compound (i) becomes `H3Si-NCS` (Silicon methyl isothiocyanate).
- Compound (iv) becomes `Si2H6O` (Silicon dimethyl ether).

4. **Determine Molecular Geometry**:
- For `CH3-NCS`, the geometry is bent due to lone pairs on nitrogen.
- For `C2H6O`, the geometry is also bent due to lone pairs on oxygen.
- For `H3Si-NCS`, the geometry is linear because of the sp hybridization of silicon.
- For `Si2H6O`, the geometry is bent due to the lone pairs on oxygen.

5. **Evaluate Basicity**:
- If X is Carbon and Y is Silicon, `H3C-NCS` is more basic than `H3Si-NCS` due to the higher electron-donating ability of carbon.

6. **Analyze Bond Angles**:
- The bond angles in compounds depend on the hybridization of the central atom and the presence of lone pairs.
- The bond angle for `H3Si-NCS` is approximately 180 degrees (linear).
- The bond angle for `H3C-NCS` is less than 180 degrees due to lone pair repulsion.

7. **Identify the Incorrect Statement**:
- The statement that X is Silicon in both compounds (i) and (iv) leading to both being linear is incorrect because while (i) is linear, (iv) is bent due to the presence of lone pairs on oxygen.

### Conclusion:
The incorrect statement regarding the given compounds is that both compounds (i) and (iv) are linear when X is silicon.