Racquel 963 Views March 29, 2017, 08:37:15 AM Question Solved Share Tweet When the serum concentration levels of a drug reach less than 3 percent, it is considered: a. Ready to interact with target cells. b. To be removed from the body. c. To be have reached the ceiling. d. Antagonistic. Maryanna March 29, 2017, 08:39:02 AM #1 Answer b.To be removed from the body. Carlena March 29, 2017, 08:52:26 AM #2 This is great.