21) Zephyros Corporation had estimated manufacturing overhead costs for the coming year to be $301,000. The total estimated direct labor hours and machine hours for the coming year are 7000 and 13,000, respectively. Manufacturing overhead costs are allocated based on direct labor hours. What is the predetermined overhead allocation rate? (Round your answer to the nearest cent.) A) $15.05 per direct labor hour B) $1.86 per machine hour C) $23.15 per machine hour D) $43.00 per direct labor hour