Sheffield Corp. has a materials price standard of $2.00 per pound. 4900 pounds of materials were purchased at $2.20 a pound. The actual quantity of materials used was 4900 pounds, although the standard quantity allowed for the output was 4000 pounds. Sheffield Corp.'s materials quantity variance is:_____.
a. $1980 U.
b. $1800 F.
c. $1800 U.
d. $1980 F.