Calculate the price elasticity of demand given initial and final prices and quantities.

Initial Price ($P_1$) = N20
Final Price ($P_2$) = N80
Initial Quantity ($Q_1$) = 300 units
Final Quantity ($Q_2$) = 500 units

The formula for point elasticity of demand is:

Change in quantity ($\Delta Q$) = $Q_2 - Q_1 = 500 - 300 = 200$ units
Change in price ($\Delta P$) = $P_2 - P_1 = 80 - 20 = 60$ N

This value is approximately 0.22.

The final answer is $\text{B) 0.22}$.