Which of the following is an example of an asymmetric information problem?

a$.$ A corporation manipulates its financial information to avoid disclosing a large loss from its operations in China.

b$.$ A corporation relocates to Ireland to take advantage of lower corporate tax rates.

c$.$ A corporation releases toxic wastes into a river.

d$.$ A stock analyst rates a stock higher than it deserves because the securities firm she works for wants to obtain business from the corporation that issued the stock.