Choose the features present in only male frog 

Options

A. copulatory pad on `1^(st)` digit fore limb
B. vocal sacs
C. copulatory organs
D. 1 and 2

Answer

To identify the features present in only male frogs, we can analyze the options provided and understand their significance in male frogs.

### Step-by-Step Solution:

1. **Understanding the Options**:
- The options given are:
1. Copulatory pad on the first digit of the forelimb
2. Vocal sac
3. Copulatory organs
4. One and two (which means both 1 and 2)

2. **Identifying Male-Specific Features**:
- **Vocal Sac**: Male frogs possess vocal sacs that allow them to produce loud croaking sounds, especially during the mating season. This feature is used to attract female frogs. Therefore, this is a male-specific feature.
- **Copulatory Pad**: Male frogs have a copulatory pad (also known as nuptial pad) located on the first digit of their forelimb. This pad helps them grasp the female during mating. Thus, this is also a male-specific feature.
- **Copulatory Organs**: Male frogs do not have distinct copulatory organs like some other animals. Instead, they rely on the copulatory pads for mating. Hence, this option is not specific to male frogs.

3. **Conclusion**:
- Based on the analysis, the features present only in male frogs are:
- Copulatory pad on the first digit of the forelimb (Option 1)
- Vocal sac (Option 2)
- Therefore, the correct answer is **Option 4: One and Two**.

### Final Answer:
The features present in only male frogs are the copulatory pad on the first digit of the forelimb and the vocal sac. Thus, the correct answer is **Option 4: One and Two**.