AThe first presents a development that the argument seeks to show will have certain disadvantages; the second is introduced as a consideration likely to offset one of those disadvantages.
BThe first presents a development that the argument predicts will have a certain impact; the second acknowledges a consideration that weighs against that prediction.
CThe first supplies a context for the argument; the second is a part of the evidence presented as support for the argument's conclusion.
DThe first is evidence provided to support an intermediate conclusion that is drawn in support of the argument's main conclusion; the second is that intermediate conclusion.
EThe first and the second each provide evidence in support of the argument's main conclusion.