Pet_supplies: Calculate each rep's commission on each invoice total. Be sure to round the commission earned on each invoice to the penny ($10.11 vs $10.108) in SQL.
a) ROUND(commission_rate * invoice_total, 2)
b) TRUNCATE(commission_rate * invoice_total, 2)
c) CEILING(commission_rate * invoice_total)
d) FLOOR(commission_rate * invoice_total)