Crane Creations purchased 10200 feet of copper tubing at a price of $2.60 per foot and used 9900 feet during the period. The standard quantity allowed for the units produced is 9700 and the standard price of the copper tubing is $2.70 per foot. What is Crane Creations' direct materials quantity variance for the period? $1350 unfavorable $540 unfavorable O $810 unfavorable O $520 unfavorable