In order to predict the number of heart attacks caused in a year in Illinois, a multiple regression model is used with the following explanatory variables. The coefficients of each of the variables are: Hypertension (yes/no) (4.67), Smoker (yes/no) (1.98), Moderate exercise three times per week (yes/no) (2.67), Bi-annual health check-ups (yes/no) (0.16). Which of these explanatory variables have the maximum impact on the response variable?