A decrease in supply will cause the smallest increase in price when

Both supply and demand are elastic.

Explanation:

Demand or supply elasticity is defined as elasticity or responsiveness with more than one numerical value, which indicates their high response to the change in price.  

Elastic demand: It is the percentage change in quantity demanded due to the change in price in absolute value of the product.

The elasticity of supply: It is defined as the response of the quantity of a good supplied to a change in the price of the good. Likely to be positive in output.

FORMULA; Elasticity of supply=

Due to the decrease in the supply of goods in the market, it leads to the scarcity of goods, therefore there is an increase in the price of goods.

b. condominum i think