What is demand in economics ? elaborate pls

Demand is a quantity of a commodity which a consumer wishes to purchase at a given level of price and during a specified period of time. In other words, demand for a commodity refers to the desire to buy a commodity backed with sufficient purchasing power and the willingness to spend.

c is the answer for this

mali had been a state inside of the ghanaian empire. after ghana fell because of invading forces and internal disputes, mali rose to greatness under the leadership of a legendary king named sundiata, the "lion king." the songhai empire, already weakened by internal political struggles, went into decline.