$7.$ The auditors of Smith Electronics wish to limit the audit risk of material misstatement in the test of cash to $10$ They believe that inherent risk is $100\%,$ and there is a $50\%$ risk that material misstatement could have by client's system of internal control. What is the maximum detection risk the auditors should specify in their procedures of details of cash? c$.20\%$ a$.10\%.$ b$.12\mathrm{.}5\%.$ d$.50\%$