On a scale from i] to 1, the effectiveness E of a painkilling drug t hours after entering the bloodstream is displayed in the he a accompanying gure. Complete parts (a) and [b] below. ' 1112345673910\" A. Nothing can be said about the derivative at those times. {:3 B. The derivative is less than zero. C:- C. The derivative is zero. t? D. The derivative is greater than zero. [b] At what time would you estimate that the drug reaches its maximum effectiveness? t= E (Type an integer or a decimal}