Among the following, the compound that can be most readily sulphonated is:

Options

A. Benzene
B. Nitrobenzene
C. Toluene
D. Chlorobenzene

Explanation

To determine which compound can be most readily sulfonated among benzene, nitrobenzene, toluene, and chlorobenzene, we can analyze the effects of the substituents on the benzene ring.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds given are benzene, nitrobenzene, toluene, and chlorobenzene.

2. **Understand Sulfonation**: Sulfonation is an electrophilic aromatic substitution reaction where a sulfonyl group (SO3H) is introduced into the aromatic ring. The ease of sulfonation depends on the electron density of the ring.

3. **Analyze the Substituents**:
- **Benzene**: No substituents, neutral electron density.
- **Nitrobenzene (NO2)**: The nitro group is a strong electron-withdrawing group due to its -I (inductive) and -M (mesomeric) effects. It decreases the electron density on the benzene ring, making it less reactive towards electrophiles.
- **Toluene (CH3)**: The methyl group is an electron-donating group through its +I (inductive) effect. It increases the electron density on the benzene ring, making it more reactive towards electrophiles.
- **Chlorobenzene (Cl)**: The chlorine atom has a -I (inductive) effect, which decreases electron density, but it also has a +M (mesomeric) effect, which can stabilize the ring. However, the overall effect is still electron-withdrawing.

4. **Determine Reactivity**: Among these compounds:
- Nitrobenzene is the least reactive due to strong electron-withdrawing effects.
- Chlorobenzene is less reactive than benzene due to the -I effect of chlorine.
- Toluene is the most reactive due to the +I effect of the methyl group, which increases electron density and activates the ring for electrophilic attack.

5. **Conclusion**: Therefore, the compound that can be most readily sulfonated is **toluene**.

### Final Answer:
The compound that can be most readily sulfonated is **toluene**.