Explanation:

The problem of allocation of resources arises due to the scarcity of resources, and refers to the question of which wants should be satisfied and which should be left unsatisfied. In other words, what to produce and how much to produce. More production of a good implies more resources required for the production of that good, and resources are scarce.

These two facts together mean that, if a society decides to increase the production of some good, it has to withdraw some resources from the production of other goods. In other words, more production of a desired commodity can be made possible only by reducing the quantity of resources used in the production of other goods.