Vaughn Company has a materials price standard of $2.60 per kilogram. 4030 kilograms of materials were purchased at $2.30 a kilogram. The actual quantity of materials used was 3600 kilograms, although the standard quantity allowed for the output was 3450 kilograms. Vaughn Company's materials quantity variance is

$390 U.

$390 F.

$1035 F.

$1035 U.