Which of the following pairs will give displacement reactions?
NaCl solution and copper metal
(b)`MgCl_2` solution and aluminium metal
(c ) `MgCl_2` solution and aluminium metal
(d) `AgNO_3` solution and copper metal

Explanation

To determine which pairs will give displacement reactions, we need to refer to the reactivity series of metals. A displacement reaction occurs when a more reactive metal displaces a less reactive metal from its compound or solution.

### Step-by-Step Solution:

1. **Identify the Reactivity Series**:
- The reactivity series is as follows (from most reactive to least reactive):
- Potassium (K) > Sodium (Na) > Calcium (Ca) > Magnesium (Mg) > Aluminum (Al) > Zinc (Zn) > Iron (Fe) > Tin (Sn) > Lead (Pb) > Hydrogen (H) > Copper (Cu) > Mercury (Hg) > Silver (Ag) > Gold (Au) > Platinum (Pt).

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