Francke Corporation would like to determine the relative profitability of a number of jobs. For example, job H29O has revenues of $180,000 and avoidable costs of $129,600, resulting in an incremental profit of $50,400. The job requires 180 hours of the constrained resource. The job is responsible for 10% of the company's total profit for the period. What is the profitability index for job H29O?

a. $280 per hour

b. $1,400 per hour

c. 0.10

d. 0.28