The pair that contains two P - H bonds in each of the oxoacids is :

Options

A. `H_4 P_2 O_5 and H_3 PO_3`
B. `H_4 P_2 O_5 and H_4 P_2 O_6`
C. `H_3 PO_2 and H_4 P_2 O_5`
D. `H_3 PO_3 and H_3 PO_2`

Explanation

To solve the question regarding which pair contains two P-H bonds in each of the oxoacids, we will analyze the structures of the relevant oxoacids.

### Step-by-Step Solution:

1. **Identify the Oxoacids**: We need to consider the oxoacids of phosphorus. The relevant oxoacids to analyze are H3PO2, H3PO3, H4P2O6, and H4PO5.

2. **Draw the Structures**:
- **H3PO2**: The structure of H3PO2 can be represented as:
```
O
||
H - P - OH
|
H
```
In this structure, there are two P-H bonds.

- **H3PO3**: The structure of H3PO3 can be represented as:
```
O
||
H - P - OH
|
OH
```
In this structure, there is one P-H bond and one OH group.

- **H4P2O6**: The structure of H4P2O6 can be represented as:
```
O
||
H - P - O - P - OH
| |
OH OH
```
In this structure, there are no P-H bonds.

- **H4PO5**: The structure of H4PO5 can be represented as:
```
O
||
H - P - O - O
| |
OH H
```
In this structure, there are two P-H bonds.

3. **Count the P-H Bonds**:
- H3PO2 has **2 P-H bonds**.
- H3PO3 has **1 P-H bond**.
- H4P2O6 has **0 P-H bonds**.
- H4PO5 has **2 P-H bonds**.

4. **Conclusion**: From the analysis, the oxoacids that contain **two P-H bonds** are **H3PO2** and **H4PO5**.

### Final Answer:
The pair that contains two P-H bonds in each of the oxoacids is **H3PO2 and H4PO5**.

---