Upon hetaing with `Cu_(2)S` the regants that give copper metel are
(i) `CuFeS_(2)` (ii) `CuO`
(iii) `Cu_(2)O`(iv) `CuSO_(4)`

Options

A. `CuFeS_(2)`
B. `CuO`
C. `Cu_(2)O`
D. `CuSO_(4)`

Explanation

To determine which reagents can produce copper metal when heated with `Cu2S`, we will analyze each option one by one.

### Step-by-Step Solution:

1. **Analyze `CuFeS2` (Chalcopyrite)**:
- When `CuFeS2` is roasted in the presence of oxygen, it decomposes to form `Cu2S`, `FeS`, and `SO2`:
\[ 2CuFeS_2 + 5O_2 \rightarrow 2Cu_2S + 2FeS + 4SO_2 \]
- Since `Cu2S` is produced and does not yield copper metal directly upon further reaction, `CuFeS2` does not give copper metal when heated with `Cu2S`.
- **Conclusion**: `CuFeS2` is **not** a valid reagent.

2. **Analyze `CuO` (Copper(II) oxide)**:
- When `CuO` is heated, it decomposes to form `Cu2O` and oxygen:
\[ 2CuO \rightarrow Cu_2O + O_2 \]
- The `Cu2O` can then react with `Cu2S` to produce copper metal and sulfur dioxide:
\[ Cu_2O + Cu_2S \rightarrow 4Cu + SO_2 \]
- **Conclusion**: `CuO` can yield copper metal.

3. **Analyze `Cu2O` (Copper(I) oxide)**:
- When `Cu2O` is heated with `Cu2S`, it directly produces copper metal and sulfur dioxide:
\[ Cu_2O + Cu_2S \rightarrow 4Cu + SO_2 \]
- **Conclusion**: `Cu2O` can yield copper metal.

4. **Analyze `CuSO4` (Copper(II) sulfate)**:
- Upon heating, `CuSO4` decomposes to form `CuO`, `SO2`, and `O2`:
\[ 2CuSO_4 \rightarrow 2CuO + SO_2 + O_2 \]
- The `CuO` formed can further decompose to `Cu2O` and oxygen:
\[ 2CuO \rightarrow Cu_2O + O_2 \]
- Then, `Cu2O` can react with `Cu2S` to produce copper metal:
\[ Cu_2O + Cu_2S \rightarrow 4Cu + SO_2 \]
- **Conclusion**: `CuSO4` can yield copper metal.

### Final Answer:
The reagents that give copper metal upon heating with `Cu2S` are:
- (ii) `CuO`
- (iii) `Cu2O`
- (iv) `CuSO4`

Thus, the correct options are **2, 3, and 4**.