The central overlap/dispute/argument between the two passages is Should insider trading be allowed?
A's reasoning is that it should be allowed. A argues this by pointing out how insider-trading actually helps enhance the efficiency and accuracy of our stock markets.
A has an interesting twist in the end where it seems to be suggesting either :
1) Insider trading laws are hypocritical in that they do not target insider-non-trading. But, at the same time it never said directly if "insider non-trading is bad".
2) Insider trading laws are currently misguided and should focus on insider-non trading.
However, I am unsure about what exactly the last paragraph was meant to do but from a very broad level it seems to be in support of loosening insider trading law. Thankfully, it never showed up in the questions except as a trap answer choice in one of the questions
B's reasoning is that it should not be allowed. B argues that this undermines transparency, which in turn undermines trust. In turn, this weakens the ability for our capital markets to be efficient and well-functioning.