If a business reports revenues of $$\$ 200,000$$ and expenses of $$\$ 180,000$$ and had $$\$ 170,000$$ cash received from customers and $$\$ 145,000$$ cash payments for expenses, its cash flow from operating activities is:
a. $$\$ 10,000$$
b. $$\$ 20,000$$
c. $$\$ 25,000$$
d. $$\$ 55,000$$