In a certain socialist country, party members earn twice as much as no

- Party members earn twice as much as non-party members
- But Party members happen to work in the businesses that generally have higher wages
- Non-party members who also work in these particular businesses earn the same

Conclusion: higher incomes do not necessarily result from the connection with the party

We need to weaken it. We need to say that higher incomes do come due to connection with the party.

A. Besides wage increases, party members also receive other benefits.

Irrelevant. Says nothing about whether non party members receive other benefits or not.

B. Some of the most highly paid business people in that country are capitalist executives in special economic zones and are not party members.

It says that some highly paid people are not party members. So it helps to say that higher incomes do not come due to party connection. It does not weaken our conclusion.

C. Wages in many industries vary from one part of the country to another, whether or not workers are in the party.

Irrelevant.

D. Non-party members in a given industry often receive higher wage as a result of the lobbying done by party members, which in turn increases the wage for the entire industry.

This says that party members lobby for higher wage (and that is why non party members also get the same). Hence, the wage increases for the entire industry. So party members do get higher incomes. This weakens our conclusion.

E. Becoming a member of the party within a given industry or business often encourages others to follow suit.

This says that people of an industry become party members when they see other people becoming party members. So it could imply that industry with high wages might end up having many party members. But they do not get high wages because they are party members.

Answer (D)