Answer : The correct option is, (B)
Explanation :
According to the reactivity series of the elements, a chemical reaction occurs when the most reactive element displace the least reactive element and form more stable products as compared to the reactants.
Option A reaction :

In this, no reaction will occur because zinc is less reactive metal as compared to aluminium. So, zinc will not displace the aluminium.
Option B reaction :

In this, the reaction will occur because sodium is more reactive metal as compared to calcium. So, sodium will displace the calcium easily.
Option C reaction :

In this, no reaction will occur because hydrogen is less reactive metal as compared to magnesium. So, hydrogen will not displace the magnesium.
Option D reaction :

In this, no reaction will occur because calcium is less reactive metal as compared to barium. So, calcium will not displace the barium.
Option E reaction :

In this, no reaction will occur because barium is less reactive metal as compared to lithium. So, barium will not displace the lithium.
Hence, the option B reaction will form products that are more stable than the reactants.
The reactivity series of the elements are shown below.