Vera Company wants to develop a cost function for its maintenance costs to estimate such costs the coming year. The following data are available: Month Direct Labour Hours Maintenance Costs Incurred June 4,000 $ 900 July 6,500 1,325 August 7,000 1,500 September 5,500 1,150 Using the high-low method, what is the cost function for maintenance costs? $500 + $1.00 per direct labour hour $300 + $1.50 per direct labour hour $100 + $0.20 per direct labour hour $200 + $0.10 per direct labour hour