The compounds with foul odour among the following is:

Options

A.
B.
C.
D.

Explanation

To determine which compound among the given options has a foul odor, we can analyze the structures and their corresponding functional groups. Here’s a step-by-step solution:

### Step 1: Identify the Compounds
We have four compounds to analyze:
1. Benzene Isocyanide (C6H5-NC)
2. Benzene Nitrile (C6H5-CN)
3. Aniline (C6H5-NH2)
4. Nitrobenzene (C6H5-NO2)

### Step 2: Analyze the Odor of Each Compound
- **Benzene Isocyanide**: This compound contains the isocyanide group (–NC). Isocyanides are known for their foul smell.
- **Benzene Nitrile**: This compound has a nitrile group (–CN). It is known to have an almond-like odor, which is not considered foul.
- **Aniline**: This compound has an amino group (–NH2). Aniline has a characteristic odor that is often described as similar to rotten fish, which is unpleasant but not as foul as isocyanides.
- **Nitrobenzene**: This compound contains a nitro group (–NO2) and also has an almond-like odor, which is not foul.

### Step 3: Conclusion
Among the four compounds analyzed, **Benzene Isocyanide** is the one that has a foul odor. Therefore, the correct answer is:

**Option A: Benzene Isocyanide**