56. A family member is ready to have a brain scan using technetium-99*, an excited isotope with 6.0-hour half-life. The hospital makes this short-lived Tc-99* from the decay of molybdenum-99 then delivers it to the nuclear medicine department. After production of Tc-99*, the hospital staff takes 90 minutes to transport it to the operating room. What is an appropriate amount of Tc-99* to be produced by the technician-in-charge for the medical requirement of 10 mg of Tc-99*?(A) 10 mg (B) 12 mg (C) 16 mg (D) 20 mg (E) 24 mg