To test the impact of information asymmetry on the relationship between CSR and underpricing, the authors used Select one: O a. the interaction between information asymmetry and the standard deviation of the expected values from the market model O b. the interaction between CSR and the standard deviation of the expected values from the market model O c. the interaction between CSR and the standard deviation of the residuals from the market model Od the interaction between information asymmerty and the standard deviation of the residuals from the market model