- (A) Ruby actually accepts and furthers this claim. He does believe that the distribution of great wealth between commerce and industry was not equal. He believes that commerce > industry. This is Ruby's main point!
(B) You can find the part in which this is discussed in 19-22. However, Ruby doesn't necessarily challenge this but rather, he doesn't talk about this. 19-22 is really all about the author and his own findings, "It does seem as if large fortunes...alcohol or tobacco than from textiles or metal." This is clearly the author's voice.
(C) Like (A), this is also one of Ruby's main points and he definitely accepts this claim and furthers it.
(D) Ruby never really seems to challenge this. He just says that there was not a big relationship between wealth and power (govt. elite).
(E) Ah yes! Rubinstein definitely challenges this in the introduction to the 3rd paragraph: "The orthodox view...wealthiest individuals were the most powerful is also questioned by Rubinstein's study." Perfect answer!