Marginal cost is the cost of producing one ___ unit.

**The reasoning** Marginal cost answers the question: "How much MORE will it cost if I produce ONE MORE unit?" Think of a small chops vendor in Lagos. She's already made 100 packs. If she decides to make pack number 101, what extra cost does she incur? That extra flour, oil, labor for just that ONE additional pack — that's her marginal cost. The word **"marginal"** in economics always means **"at the edge"** or **"the next one."** Marginal cost specifically measures the change in total cost when you increase production by **one additional unit**. **Why the wrong options tempt you** - **A) fewer** — This would be about reducing production, not increasing it. Marginal cost looks forward (next unit), not backward. - **C) total** — Total cost is everything combined; marginal cost isolates just the *change* from one more unit. - **D) fixed** — Fixed costs don't change with production (like rent). Marginal cost is about *variable* costs that respond to output changes. **Quick takeaway** Marginal = **additional** — always remember: it's the cost of making "one MORE" unit, not fewer, not the total, not what stays fixed.