Wildhorse Creations purchased 8900 feet of copper tubing at a price of $2.70 per foot and used 8600 feet during the period. The standard quantity allowed for the units produced is 8400 and the standard price of the copper tubing is $2.80 per foot. What is Wildhorse Creations' direct materials quantity variance for the period?

$560 unfavorable

$1400 unfavorable

$840 unfavorable

$540 unfavorable