My reasoning is D; what happened to other unions of other companies have no impact on what will happen to this union.

E is relevant because if there are other companies that own gas stations, the miners' union's strategy may not work.

C is relevant because it is also miners' unions.

Hi amysky_0205,

The correct answer is E. That means it is the answer which is LEAST likely to be asked by the union members as they consider whether or not to proceed with the boycott. Of course, the reason it is LEAST likely to be asked is that it is IRRELEVANT to the aims of the boycott.

"Have other miners' unions won contracts similar to the one proposed by this union?" (answer C) is relevant (i.e. something the union members would want to know) because they would want to know if their proposal had worked elsewhere. Because it is relevant, we don't want to choose this answer.

"Have other unions that have employed a similar tactic achieved their goals with it?" (answer D) is also relevant because they would want to know if their tactics had worked elsewhere. Because it is relevant, we don't want to choose this answer.

"Do other corporations that own coal companies also own gas stations?" (answer E) is irrelevant because we are concerned about this particular gas station and coal company. This is the answer we are after!

I hope this helps.