How do we define Low Cost Advantage?

a.Low Cost Advantage only applies to firms selling commodities (undifferentiated products and services).

b.All firms must take the market price, so any competitive advantage is the result of having a lower total relative cost.

c.A low cost advantage is defined as achieving a lower total cost (not a lower price) compared to only the marginal producer (the least efficient producer that is still necessary to fill demand).

d.All of the above

e.B and C