Why Would Transparency Affect Trade Cooperation

Why would transparency affect trade cooperation?

A) A country would be more reluctant to enter into a free-trade agreement if it has little information about another country's subsidies to domestic producers.
B) Two countries with too much information about each other's tax policies would find it difficult to negotiate a free-trade agreement.
C) Countries that negotiate simpler trade agreements are more likely to suspect the other side of cheating.
D) Countries try to conceal information about their domestic policies to improve the likelihood of negotiating an effective free-trade agreement.