A consumer is said to be in equilibrium if they are able to maximize their satisfaction or utility given their budget constraint. In other words, it means that a consumer is in a situation where they have allocated their income in such a way that they cannot increase their satisfaction by reallocating their expenditure.

Therefore, the correct statement for a consumer to be in equilibrium is:

- He is able to fulfill his needs with a given level of income.

Being in equilibrium does not imply living in full comforts, fulfilling needs without consumption of certain items, or locating new sources of income. It simply means that the consumer has allocated their income in the most optimal way to meet their needs and maximize their satisfaction.