An auditors study and evaluation of the internal accounting control system made in connection with an annual audit is usually not sufficient to express an opinion on an entity system because? a. The evaluation of weaknesses is subjective enough that an auditor should not express an opinion on the internal accounting controls alone b. The audit cost benefit relationship permits an auditor to express only reasonable assurance that the system operates as designed. c. Management may change the internal accounting controls to correct weaknesses. d. Only those controls on which an auditor intends to rely are reviewed, tested and evaluated