A company estimates that it will sell N(x) units of a product after spending $x thousand on advertising, as given by N(x)equalsnegative 0.25 x Superscript 4 Baseline plus 22 x cubed minus 472.5 x squared plus 76 comma 000, where 21 less than or equalsxless than or equal 45. When is the rate of change of sales increasing and when is it decreasing

Of the following, which statement or statements accurately reflect a way in which credit can be safer than cash? i. if your credit card gets stolen, you can cancel it and get your money back. ii. it is harder to lose a single credit card than a large number of bills. iii. if a merchant does not honor the agreement, you can call the credit company and dispute the charges. a. i and iii b. ii only c. iii only d. i, ii, and iii