Concept:Supply is the quantity of goods producers are willing and able to offer for sale at a given price.
A change in supply occurs when a factor other than price affects the amount producers can sell.
Explanation:Storage facilities help producers keep goods safely until they are needed in the market.
Without enough storage, perishable or bulky goods may spoil or get damaged before sale.
When good storage facilities are available, producers can store more and increase supply later.
When storage is poor or unavailable, producers reduce output, which decreases supply.
So, availability of storage facilities is a major factor that changes supply.
Answer:B. availability of storage facilities.