Explain how the S-curve reflects the typical nature of complementarities?

In one week Alice can produce 5 pairs of shoes or 4 bookshelves while Roger can produce 10 pairs of shoes or 6 bookshelves. Alice should specialize in the production of

A) shoes. B) bookshelves. C) either shoes or bookshelves. D) neither shoes nor bookshelves.

In the figure above, the curve labeled "W" can be a

A) monopoly's demand curve. B) monopoly's marginal revenue curve. C) perfectly competitive firm's demand curve. D) perfectly competitive firm's marginal revenue curve.