V A marine manufacturer will sell N(x) power boats after spending $x thousand on advertising, as given by N(x) = 1,000- 3,870 X -, 5sxs 30. (A) Find N'(x). (B) Find N'(10) and N'(20). Write a brief verbal interpretation of these results. (A) N'(x) = (B) N'(10) = (Type an integer or a decimal.) Interpret (10). Choose the correct answer below. O A. The marine manufacturer will sell 10 power boats after spending $38.7 thousand on advertising. O B. At the $10,000 level of advertising, sales are increasing at the rate of 38.7 boats per $1,000 spent on advertising. O C. The marine manufacturer will sell 38.7 power boats after spending $10,000 on advertising. O D. At the $38.7 thousand level of advertising, sales are increasing at the rate of 10 boats per $1,000 spent on advertising. N'(20) = (Type an integer or a decimal.) Interpret N'(20). Select the correct choice below and fill in the answer box to complete your choice. O A. The marine manufacturer will sell 20 power boats after spending $ thousand on advertising. O B. At the $ thousand level of advertising, sales are decreasing at the rate of 20 boats per $1,000 spent on advertising. O C. The marine manufacturer will sell power boats after spending $20,000 on advertising. O D. At the $20,000 level of advertising, sales are increasing at the rate of boats per $1,000 spent on advertising