Final answer:
The most promising opportunity for a firm in a declining industry is to establish itself as a first mover in the post-shakeout industry.
Step-by-step explanation:
The most promising opportunity for a firm in a declining industry is to establish itself as a first mover in the post-shakeout industry. As the industry declines, there will likely be consolidation and shakeouts, with some firms exiting the market. By being a first mover, a firm can position itself to take advantage of the post-shakeout industry where there might be less competition and potentially more growth opportunities. This can give the firm a competitive advantage and increase its chances of success.