For Roberts Company, the predetermined overhead rate is $70\%$ of direct labor cost. During the month, $$720,000$ of factory labor costs are incurred of which $$200,000$ is indirect labor. Actual overhead incurred was $$360,000.$ The amount of overhead debited to Work in Process Inventory should be:

a$.$ $$360,000$

b$.$ $$504,000$

c$.$ $$520,000$

d$.$ $$364,000$