Which of the Following Is Not a Reason It Is

Which of the following is not a reason it is harder to unionize in the fast growing service industry?

A) Service sector jobs are often in small firms, making it difficult to organize large numbers of employees across the industry.
B) Service industry jobs are often standardized, reducing the need for unions to negotiate working conditions.
C) Employees in the service sector often work more closely with management.
D) Service industry jobs are more varied, making it harder to negotiate as a group.