Answer: Option (a) is correct.
Explanation:
Materials Costs = Units × Unit Material Cost
             = 6,000 × $8
             = $48,000
Conversion costs = Units × Percentage Complete × Unit Conversion Cost
               = 6,000 × 75% × $12
               = $54,000
Ending Work-In Process Inventory:
= Materials Costs  + Conversion Costs
= $48,000 + $54,000
= Â $102,000