Carbene intermediates are produced by the photolysis of diazomethane `(CH_2N_2)` or kenene `(CH_2 = C = O)`. They are also produced by the reaction of `CHX_3` with base or by Simmons-Smith reaction. There are two types of carbenes, singlet and triplet. They are so called due to their spin state.
Singlet and triplet carbene are same in :

Options

A. Types of hybridisation
B. Number of unshared `overline e` pairs (or `LP overline e^, s`)
C. Number of `sigma-bonds`
D. Bond angle

Explanation

To solve the question regarding the similarities between singlet and triplet carbenes, we will analyze the properties of both types of carbenes step by step.

### Step-by-Step Solution:

1. **Understanding Carbenes**:
- Carbenes are neutral species containing a carbon atom with only six valence electrons, resulting in a divalent state. They can exist in two forms: singlet and triplet.

2. **Singlet Carbene**:
- In singlet carbenes, both of the valence electrons occupy the same orbital, leading to a paired state.
- Example: The structure of singlet carbene can be represented as R2C: where the colon indicates the lone pair of electrons.

3. **Triplet Carbene**:
- In triplet carbenes, the two valence electrons occupy different orbitals, leading to an unpaired state.
- Example: The structure of triplet carbene can be represented as R2C with one electron in one orbital and another in a different orbital.

4. **Hybridization**:
- Singlet carbenes typically exhibit sp² hybridization, while triplet carbenes can exhibit either sp or sp² hybridization.
- Since they differ in hybridization, this means they do not share this property.

5. **Number of Unshared Electron Pairs**:
- Both singlet and triplet carbenes have no lone pairs of electrons. However, singlet carbenes have paired electrons, while triplet carbenes have two unpaired electrons.
- Therefore, they do not share this property either.

6. **Number of Sigma Bonds**:
- Both singlet and triplet carbenes have the same number of sigma bonds. This is a key similarity between the two types of carbenes.
- For example, both can form two sigma bonds with substituents.

7. **Bond Angles**:
- The bond angles in singlet and triplet carbenes differ due to their different hybridization states. Therefore, they do not share this property.

### Conclusion:
From the analysis, we conclude that the only property that singlet and triplet carbenes share is the **number of sigma bonds**.

### Final Answer:
**Singlet and triplet carbenes are the same in the number of sigma bonds.**