F18 Custom Tile Works budgeted 2.5 hours of direct labor per unit at $12.20 per hour to produce 520 hand-painted mosaic tiles. The 520 tiles were completed using 1,400 hours of direct labour at $12.50 per hour. What is the direct labor price variance? a. $390 favorable b. $390 unfavorable c. $420 favorable d. $420 unfavorable