Based on the given information, Figure 4-3 shows Consumer 1 and Consumer 2. To determine the market quantity demanded at a price of $10, we need to consider the individual quantities demanded by each consumer at that price.
However, the quantities demanded by each consumer at a price of $10 are not provided in the question. Without this information, we cannot accurately determine the total market quantity demanded at that price.
Therefore, we cannot definitively answer the question. The options provided in the question (0 units, 5 units, and 8 units) are not applicable without additional information on the quantities demanded by each consumer.
To accurately determine the market quantity demanded, we would need the individual demand curves or schedules for Consumer 1 and Consumer 2 at a price of $10. With this information, we could add the quantities demanded by each consumer to obtain the total market quantity demanded.
In summary, without the specific quantities demanded by Consumer 1 and Consumer 2 at a price of $10, we cannot determine the market quantity demanded at that price.