Explanation:

To find the price elasticity of demand, you can use the formula:

$$ \text{Price Elasticity of Demand} (E_d) = \frac{\% \text{ Change in Quantity Demanded}}{\% \text{ Change in Price}} $$

- Calculate the percentage change in quantity demanded:

$$ \%- \text{change in quantity demanded} = \frac{10 - 5}{5} \times 100 = 100\% $$

- Calculate the percentage change in price:

$$ \%- \text{change in price} = \frac{3 - 4}{4} \times 100 = -25\% $$

- Plug values into the formula:

$$ E_d = \frac{100\%}{-25\%} = -4 $$

- Since elasticity is expressed as a positive value:

$$ E_d = 4 $$

- So, the correct option is Option:2, 4