Managers must be prepared to modify their strategy except when

a$.$

evidence is mounting that the current strategy is becoming less effective.

b$.$

rivals announce their monthly profit margins in public.

c$.$

rivals make or adjust moves in the market due to the shifting needs of buyers.

d$.$

changing circumstances affect performance and the desire to improve the current strategy.

e$.$

encountering stagnating market conditions and increasingly restrictive new customer acquisition opportunities.