Most Studies Have Shown That the Initial Stages of the Pharmaceutical

Most studies have shown that the initial stages of the pharmaceutical manufacturing process usually give rise to _________________ , while after the large fixed (sunk) costs are finally paid off, manufacturing of pharmaceutical products exhibits ________________________________.

A) economies of scale; diseconomies of scale.
B) diseconomies of scale; economies of scale.
C) constant returns to scale; diseconomies of scale.
D) economies of scale; constant returns to scale.
E) diseconomies of scale; constant returns to scale.