In the context of rational behavior and utility maximization, how does an individual decide to consume an additional unit of a good based on marginal cost?

When an individual decides whether to consume an additional unit of a good, they think about the satisfaction or utility that this extra unit will bring them. This is called marginal utility, which is the additional satisfaction gained from consuming one more unit. At the same time, they also consider the marginal cost, which is the cost of obtaining that extra unit. If the marginal utility of the good is greater than the marginal cost, it makes sense for the person to consume that additional unit because they are gaining more satisfaction than they are spending. For example, if a person enjoys eating pizza and the satisfaction from one more slice is worth $3, but the price of that slice is only $2, they would choose to buy the slice because the benefit outweighs the cost.