Beta Corporation is planning operations for the coming year. Beta uses normal costing and applies overhead on the basis of direct labor hours. The estimated overhead cost amounts to $10,000,000, estimated direct labor hours are 100,000, estimated direct labor cost amounts to $3,100,000, and estimated direct materials cost is $22,000,000. What is Beta's predetermined overhead rate? 

a $45 per direct labor hour 

b. $100 per direct labor hour 

c. $60 per direct labor hour 

d. $31 per direct labor hour