Of the following statements:
(a) `C_(6)H_(5)N=CH-C_(6)H_(5)` is a Schiff's base
(b) A dye is obtained by the reaction of aniline and `C_(6)H_(5)N=NCl`
(c) `C_(6)H_(5)CH_(2)NH_(2)` on treatment with `[NaNO_(2) + HCl]` gives diazonium salt
(d) p-Toluidine in treatment with `[HNO_(2) + HCl]` gives diazonium salt

Options

A. Only (a) and (b) are correct
B. Only (a) and (c) are correct
C. Only (c) and (d) are correct
D. (a),(b) and (d) are correct

Answer

To solve the question regarding the correctness of the statements about amines, we will analyze each statement step by step.

### Step 1: Analyze Statement (a)
**Statement:** `C_(6)H_(5)N=CH-C_(6)H_(5)` is a Schiff's base.

**Explanation:**
A Schiff's base is formed when a primary amine reacts with an aldehyde or ketone, resulting in a compound with a C=N (carbon-nitrogen double bond) linkage. Here, `C_(6)H_(5)N=CH-C_(6)H_(5)` has a C=N linkage, indicating that it is indeed a Schiff's base.

**Conclusion:** Statement (a) is **correct**.

### Step 2: Analyze Statement (b)
**Statement:** A dye is obtained by the reaction of aniline and `C_(6)H_(5)N=NCl`.

**Explanation:**
Aniline (C6H5NH2) can react with a diazonium salt (like `C_(6)H_(5)N=NCl`) to form azo dyes. The reaction between aniline and the diazonium salt leads to the formation of an azo compound, which is a type of dye.

**Conclusion:** Statement (b) is **correct**.

### Step 3: Analyze Statement (c)
**Statement:** `C_(6)H_(5)CH_(2)NH_(2)` on treatment with `[NaNO_(2) + HCl]` gives diazonium salt.

**Explanation:**
`C_(6)H_(5)CH_(2)NH_(2)` is a primary amine (benzylamine). When treated with sodium nitrite (NaNO2) and hydrochloric acid (HCl), it does not form a stable diazonium salt. Instead, the intermediate formed is unstable and decomposes, typically leading to the formation of alcohol rather than a stable diazonium salt.

**Conclusion:** Statement (c) is **incorrect**.

### Step 4: Analyze Statement (d)
**Statement:** p-Toluidine in treatment with `[HNO_(2) + HCl]` gives diazonium salt.

**Explanation:**
p-Toluidine (C6H4(CH3)NH2) is a primary aromatic amine. When treated with NaNO2 and HCl, it forms a stable diazonium salt. This reaction is characteristic of primary aromatic amines, and the resulting diazonium salt is stable.

**Conclusion:** Statement (d) is **correct**.

### Final Conclusion
Based on the analysis:
- Statement (a) is correct.
- Statement (b) is correct.
- Statement (c) is incorrect.
- Statement (d) is correct.

Thus, the correct statements are (a), (b), and (d).

### Answer:
The correct statements are **(a), (b), and (d)**.