Answer:
A. credit to Unearned Service Revenue of $24,000
Step-by-step explanation:
Total cost = $90,000 + $60,000 + $30,000 = $180,000
Unearned service training service revenue = ($30,000 ÷ $180,000) × $144,000 = $24,000
Therefore, the correction option is A. credit to Unearned Service Revenue of $24,000.