The collective strength of the five forces can help determine a. what specific strategy each industry participant should pursue.
b. the strengths and weaknesses of each company in the industry.
c. if companies in the industry can reasonably expect to earn decent profits.
d. a broad view of the industry's macro-environment.

c. if companies in the industry can reasonably expect to earn decent profits.

Explanation:

The Porter’s five forces of competition is a framework developed by Michael E. Porter in 1979, it is used to measure and analyze an organization's competitiveness in a business environment.

The Porter's five forces of competition framework are:

1. The bargaining power of suppliers.

2. The bargaining power of customers.

3. Threat posed by substitute products.

4. Threats posed by new entrants.

5. Threats posed by existing rivals in the industry.

A competitive force can be defined as all of the variables and factors that are capable of threatening the profitability, continuous growth and development of a business firm. Also, the competitive forces differs from one industry to another and as such they are never the same.

Hence, the collective strength of the five forces can help determine if companies in the industry can reasonably expect to earn decent profits.

answer; engaging in effective public relations;