The following labor standards have been established for a particular product:

Standard labor-hours per unit of output: 2.4 hours

Standard labor rate: 15.45 per hour

The following data pertain to operations concerning the product for the last month:

Actual hours worked: 5,400 hours

actual total labor cost: 85,860

actual output: 2,200 units

What is the labor rate variance for the month?

a) 1,908 U

b) 2,430 U

c) 4,284 U

d) 4,284 F