The correct answer is: A higher indifference curve shows a higher level of satisfaction.
An indifference curve is a graph that shows all the combinations of goods and services that provide the same level of satisfaction to a consumer. A higher indifference curve represents a higher level of satisfaction because it contains combinations of goods and services that the consumer prefers to the combinations on lower indifference curves.
Option B is incorrect because a higher level of production does not necessarily mean a higher level of satisfaction. For example, a consumer might be satisfied with a small amount of goods and services if they have all of their basic needs met.
Option C is incorrect because a higher level of income does not necessarily mean a higher level of satisfaction. For example, a consumer might be satisfied with a low income if they have all of their basic needs met and they are not materialistic.
Option D is the correct answer because it is the only option that is consistent with the definition of an indifference curve.