Vitality Industries uses a weighted average process$-$costing system. All materials are added at the beginning of the process; conversion costs are incurred evenly throughout production. The company finished $40,000$ units during the period and had $15,000$ units in progress at year$-$end, the latter at the $40\%$ stage of completion. Total material costs amounted to $$220,000$; conversion costs were $$414,000.$ What is the ending WIP cost?

a$.$ $$114,000$

b$.$ $$78,000$

c$.$ $$195,000$

d$.$ $$54,000$