Francis Company uses flexible budgets. At normal capacity of 8,000 vases, budgeted manufacturing variable overhead is $48,000. If Francis had actual variable overhead costs of $58,500 for 9,000 vases produced, what is the difference between actual and budgeted costs for variable overhead?
a. $1,500 unfavorable
b. $1,500 favorable
c. $4,500 unfavorable
d. $10,500 favorable