Choice "C" is correct. Due care in performing an audit requires a member to plan and supervise adequately any professional activity for which he or she is responsible. This includes critical review at every level of supervision of the work done and the judgment exercised by those assisting in the examination.
Choice "b" is incorrect. An auditor need not examine all available corroborating evidence. Only sufficient appropriate evidence to provide the auditor with a reasonable basis for forming an opinion is required.
Choice "a" is incorrect. Because of the characteristics of illegal acts, an audit conducted in accordance with generally accepted auditing standards provides no assurance that illegal acts will be detected or that any contingent liabilities that may result will be disclosed.
Choice "d" is incorrect. The attainment of the proper balance between professional experience and formal education is related to the training and proficiency requirement rather than to the requirement of due care.