Which of the following reactions will occur?

Options

A. ` 2Ag + Cu(NO_3)_2 to 2AgNO_3 + Cu`
B. `Cu+ ZnSO_4 to CuSO_4 +Zn`
C. `2Ag + H_2SO_4 to Ag_2SO_4 + H_2`
D. `2Al + 3FeSO_4 to Al_2(SO_4)_3 + 3Fe`

Explanation

To determine which of the given reactions will occur, we need to analyze the reactivity of the metals involved in each reaction using the reactivity series. The reactivity series ranks metals from most reactive to least reactive, and a more reactive metal can displace a less reactive metal from its compound.

### Step-by-Step Solution:

1. **Identify the Reactions**:
We have four reactions to analyze:
- Reaction A: Ag + CuSO4
- Reaction B: Cu + ZnSO4
- Reaction C: Ag + H2SO4
- Reaction D: Al + FeSO4

2. **Check Reaction A (Ag + CuSO4)**:
- Silver (Ag) is attempting to displace copper (Cu) from copper sulfate (CuSO4).
- According to the reactivity series, copper is more reactive than silver.
- Since silver cannot displace copper, **this reaction will not occur**.

3. **Check Reaction B (Cu + ZnSO4)**:
- Copper (Cu) is attempting to displace zinc (Zn) from zinc sulfate (ZnSO4).
- According to the reactivity series, zinc is more reactive than copper.
- Since copper cannot displace zinc, **this reaction will not occur**.

4. **Check Reaction C (Ag + H2SO4)**:
- Silver (Ag) is attempting to displace hydrogen (H) from sulfuric acid (H2SO4).
- According to the reactivity series, hydrogen is more reactive than silver.
- Since silver cannot displace hydrogen, **this reaction will not occur**.

5. **Check Reaction D (Al + FeSO4)**:
- Aluminum (Al) is attempting to displace iron (Fe) from iron(II) sulfate (FeSO4).
- According to the reactivity series, aluminum is more reactive than iron.
- Since aluminum can displace iron, **this reaction will occur**.

### Conclusion:
The only reaction that will occur is **Reaction D: Al + FeSO4**.