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

Standard labor-hours per unit of output	8.4	hours
Standard labor rate	$15.70	per hour

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

Actual hours worked	10,500	hours
Actual total labor cost	$162,330
Actual output	1,400	units

What is the labor rate variance for the month?

a)$2,520 F

b)$336 U

c)$2,520 U

d)$336 F