In This Experiment,the Risk-Taking Propensity of 90 Inner City Drug

In this experiment,the risk-taking propensity of 90 inner city drug users was measured using a repeated measures test called the Behavioral Analogue Risk Task (BART;Lejuez et al. ,2002) .The higher the BART score,the higher the risk-taking propensity.Participants also filled out questionnaires so that their Psychopathic Personality Inventory (PPI) scores could be computed.PPI scores are used to detect psychopathic traits in a covert manner and are a common indicator of one's level of psychopathy.The main goal of the experiment was to examine the relationship between risk-taking (measured by BART) based on one's level of psychopathy (measured by PPI on a scale of 0-100) ,gender (1 for male and 2 for female) ,and heroin use (1 for heroin use and 0 for no heroin use) .Below is a partial output of a multiple regression analysis. How many explanatory variables are in this study?

A) One
B) Two
C) Three