4.a. What does it mean, if company's operating cash flow is negative for a particular period and how does it impact the investment and financing activities of a company? Explain briefly. 4.b. Explain briefly, how could a company's change in NWC be negative in a given year. What about net capital spending? 4.c. Is it possible for a company to pay dividends when it has a negative net income for the year? Could this happen in the long run? Explain briefly