The correct option is B Secondary
Auditing is an examination of the accounting books and the relative documentary evidence so that an auditor may be able to find out the accuracy of figures and may be able to make report on the balance sheet and other financial statements which have been prepared by the end of accounting is the beginning of auditing.
Auditing main purpose or object is to find the opinion of an auditor about correctness and reliability of accounts and the financial position of the business concern.
Thus, detection and prevention of fraud is the secondary objective of auditing.