transparency

In discussing the Abacus CDO case, Alan Murray, deputy managing editor of the Wall Street Journal, observed: “Markets don’t work if you don’t have good information and you don’t have transparency. And this [CDO] is terribly lacking in transparency.”
a. What is “transparency” in this instance?
b. Why won’t financial markets work without good information and transparency?
c. What information was lacking and who lacked it in the Abacus CDO case?