During the month of January $,$ direct material cost totaled $$39,000$ and direct labor cost totaled $$16,000.$ If total manufacturing overhead cost was $$28,000,$ the prime and conversion cost amounted to : Select one : a $.$ $$39,000$ and $$12,000$ b$.$ $$55,000$ and $$44,000$ c$.$ $$23,000$ and $$28,000$ d$.$ $$39,000$ and $$28,000$