Onyx company has prepared a static budget at the beginning of the month. at the end of the month, the following information has been retrieved from the records.

static budget:
sales volume: 1,000 units: prices: $70 per unit
variable expense: $32 per units:
fixed expenses: $37,500 per month
operating income: $500

actual results:
sales volume: 990 units: price $74 per unit
variable expenses: $35 per unit: fixed expenses: $33,000 per month
operating income: $5,610

calculate the flexible budget variance for fixed expenses.

a.$4,500u
b. $4,500f
c. $0
d. $5,490