Assume the Perpetual Inventory Method Is Used

Assume the perpetual inventory method is used.
1) Marathon Company purchased merchandise inventory that cost $8,000 under terms of 2/10, n/30 and FOB shipping point.
2) Marathon paid freight cost of $500 on the merchandise.
3) Marathon made payment to the supplier within the discount period.
4) All of the goods were sold to customers on account for $12,000.
As a result of Marathon's four transactions above, the net amount of the company's cash flow from operating activities is

A) $8,340 outflow.
B) $12,000 inflow.
C) $8,500 outflow.
D) $3,660 inflow.