Byters on Call provides computer repairs on-site and has a contribution margin ratio of 32%, a contribution margin per service call of $5, and fixed costs of $21,160 per month. During March, it made 5,000 service calls. How much will Byters on Call's profit increase if 160 more service calls are made?
a) $1,354
b) $800
c) $6,771
d) $4,232