Arrange the elements Zn, Sn, Ca and Al in the increasing order of their reactivity for replacing Cu from `CuSO_4` solution:

Options

A. `Zn gt Sn gt Ca gt Al `
B. `Ca gt Al gt Zn gt Sn`
C. `Ca gt Al gt Sn gt Zn`
D. `Ca gt Sn gt Zn gt Al`

Explanation

To arrange the elements Zn (Zinc), Sn (Tin), Ca (Calcium), and Al (Aluminum) in the increasing order of their reactivity for replacing Cu (Copper) from CuSO₄ (Copper Sulfate) solution, we need to refer to the reactivity series of metals.

### Step-by-Step Solution:

1. **Understand the Reactivity Series**: The reactivity series is a list of metals arranged in order of decreasing reactivity. Metals that are higher in the series can displace metals that are lower in the series from their compounds.

2. **Identify the Position of Each Metal**:
- **Calcium (Ca)**: Calcium is highly reactive and is placed above Zinc in the reactivity series.
- **Zinc (Zn)**: Zinc is also reactive and is placed above Copper but below Calcium.
- **Aluminum (Al)**: Aluminum is more reactive than Zinc and is placed above Zinc in the reactivity series.
- **Tin (Sn)**: Tin is less reactive than Zinc and is placed below Copper in the reactivity series.

3. **List the Metals in Order of Reactivity**:
- From the reactivity series, we can summarize the order as follows:
- Calcium (Ca) > Aluminum (Al) > Zinc (Zn) > Tin (Sn) > Copper (Cu)

4. **Arrange in Increasing Order of Reactivity**:
- Since we need to arrange them in increasing order of their reactivity to replace Copper from Copper Sulfate, we will list them from least reactive to most reactive:
- Tin (Sn) < Zinc (Zn) < Aluminum (Al) < Calcium (Ca)

### Final Answer:
The increasing order of reactivity for replacing Cu from CuSO₄ solution is:
**Sn < Zn < Al < Ca**