plesse help with all parts

A small company of science writers found that its rate of profit (in thousands of dollars) after t years of operation is given by P(t)=(3t+6)(t2+4t+6) (a) Find the total profit in the first five years. (b) Find the profit in the seventh year of operation. (c) What is happening to the annual profit over the long run? (a) The total profit in the first five years is $ (Round to the nearest dollar as needed.) (b) The profit in the seventh year of operation $ (Round to the nearest dollar as needed.) (c) Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. Over the long run, the annual profit is increasing without bound. B. Over the long run, the annual profit is decreasing without bound. C. Over the long run, the annual profit is decreasing and approaching $ (Round to the nearest dollar as needed.) D. Over the long run, the annual profit is increasing and approaching $ (Round to the nearest dollar as needed.)