He had hoped his chair(s) would go on to be mass-produced, not hand-crafted. As a matter of fact, he had hopes that much of his furniture would be mass-produced--he aimed for simplicity in construction. The pieces of wood that comprised the Red Blue Chair were the standard lumber sizes readily available at the time.
It would say that the technique that was discontinued during the swing era was Collective improvisation (option B) This might be because improvisation was connected to Jazz and Free Jazz music. Swing jazz is based on the off-beat or music pulse.