The correct answer is: A. a statement of fact.
The law of diminishing marginal utility states that as a consumer increases consumption of a good or service, the marginal utility (additional satisfaction) derived from each additional unit decreases. This is because as a consumer consumes more of a good or service, they become less and less hungry for it.
For example, if you are very hungry and eat a piece of bread, you will get a lot of satisfaction from it. However, if you eat another piece of bread, you will not get as much satisfaction from it. This is because you are not as hungry anymore.
The law of diminishing marginal utility is a fundamental concept in economics. It is used to explain why consumers do not always buy the most of a good or service. It is also used to explain why prices tend to fall as more of a good or service is produced.
A statement of fact is a statement that is true. It is not a hypothesis or a law. A hypothesis is a statement that is proposed as an explanation for a phenomenon. A law is a statement that is based on repeated observation and experimentation.
In the case of the law of diminishing marginal utility, it is a statement of fact that has been repeatedly observed and experimented with. It is not a hypothesis or a law.