Thanks for the question! (C) weakens because those lines are saying that individuals in the original position think that everyone should get some minimum. but if (C) is true, then some people might just go for the biggest amount of the primary good.
(D) is wrong because it is irrelevant. If it’s true, people will still want the at least minimum primary goods, and more. So in the original position, they’d still want everyone to have primary goods.
Hope this helps! Feel free to ask any other questions that you might have.
