I understand that the marginal cost is the cost of producing one additional unit of a good or service.
Is it correct to say that the opportunity cost is part of the marginal cost (I'm trying to figure out what is meant by this picture below)?
And secondly, is this statement correct "whatever a producer receive aboves its opportunity cost of providing the good/service is its producer surplus?" I read this online. Isn't it suggesting that the opportunity cost is the marginal benefit (because price received minus the points on the supply curve is producer surplus)?