Match the following items with one of the following three selections: a. Demographic variable b. Dependent variable or c. Independent variable - Perception of pain - Age - Exercise program - Incidence of phlebitis A. Select a. demographic variable, b. Dependent variable or c. Independend variable B. Select a. demographic variable, b. Dependent variable or c. Independend variable C. Select a. demographic variable, b. Dependent variable or c. Independend variable D. Select a. demographic variable, b. Dependent variable or c. Independend variable