Choice "C" is correct. Missing user controls in the end-user policy of an organization exposes the organization to using potentially incorrect end-user developed files and to incorrectly attributing the same credibility to those files as the organization places on their mainframe-generated data. End-user files operating independently of mainframe controls are subject to undetected errors. End-user files associated with highly complex computations, such as actuarial calculations, are particularly vulnerable to data integrity issues since the validity of amounts is not always intuitively or obviously right or wrong.Choice "a" is incorrect. Management information is not necessarily limited by EUC files, but data may be compromised or incorrect.Choice "d" is incorrect. Management's response time to competitive pressures will not be delayed but the quality of decision making may be compromised by bad data. Actuarially determined liabilities in an insurance environment based on flawed EUC files might result in bad pricing for an insured risk.Choice "b" is incorrect. EUC files might be faster (more efficient) than mainframe data. Sadly, in this instance, the "efficiency" may be a byproduct of poor controls that produce bad data quickly.