Brass contains:

Options

A. Cu + Sn
B. Cu + Ni
C. Cu + Zn
D. Mg + Al

Answer

To determine what brass contains, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Alloys**:
- An alloy is a mixture of two or more elements, where at least one of the elements is a metal. Alloys are created to enhance certain properties such as strength, corrosion resistance, and ductility.

2. **Identifying Brass**:
- Brass is specifically known as an alloy that primarily consists of copper and zinc.

3. **Differentiating from Other Alloys**:
- To clarify, we can compare brass with other common alloys:
- **Bronze**: An alloy of copper and tin.
- **Cupronickel**: An alloy of copper and nickel.
- **Magnox**: An alloy of magnesium and aluminum.

4. **Composition of Brass**:
- The proportions of copper and zinc in brass can vary, which allows for different mechanical and electrical properties. Typically, brass contains about 55% to 95% copper and 5% to 45% zinc.

5. **Conclusion**:
- Therefore, the answer to the question "What does brass contain?" is that brass is an alloy of **copper and zinc**.

### Final Answer:
Brass contains copper and zinc.