Question

The price of coffee rose sharply last month, while the quantity sold remained the same. five people suggest various explanations:

Answer 1

The price of coffee rose sharply last month, while the quantity sold remained the same can be a  result of several situations and therefor there are several explanations that are possible:
Demand increased, but supply was perfectly inelastic.
Demand increased, but supply decreased at the same time.
Supply decreased, but demand was perfectly inelastic.

Answer 2

The suggestions of the explanations were not included however, if the price of coffee increased significantly but the quantity sold remained the same, the demand for coffee did not change with the increase in price. Those who want to purchase coffee were not affected by the increase of price. Demand increased but the supply was perfectly inelastic.