DrSullivan Is Conducting a Clinical Trial to Determine If Vitamin

Dr.Sullivan is conducting a clinical trial to determine if vitamin Z can improve test performance of students in an introductory college nutrition course.Dr.Sullivan puts all the student names in a hat and draws names to determine if they will be placed in the control or the experimental group.The experimental group receives a capsule of vitamin Z and the control group a "sugar pill" that tastes and looks identical to the vitamin Z capsule.Neither Dr.Sullivan nor the participants knows who is receiving which treatment.This experiment is BEST described as

A) single-blind, randomized.
B) placebo-controlled, self-selected.
C) placebo-controlled, single-blind, randomized.
D) placebo-controlled, double-blind, randomized.