Option C is true about the relationship between price and supply:
C. When prices for a good are high, producers are encouraged to sell more of it.
The law of supply states that as the price of a good increases, the quantity supplied of that good also increases. This is because producers are incentivized to increase their production and sell more of the good to take advantage of the higher prices, as it will lead to higher profits. Conversely, when the price of a good is low, producers are less incentivized to produce and sell that good, as it will lead to lower profits. So, when the price of a good is high, the supply of that good is likely to increase as producers try to take advantage of the favorable market conditions.