Which of the following statements about the correlation coefficient r is true? Select one or more options.
1) If the correlation coefficient is 1, then the slope of the regression line is also 1.
2) If the correlation coefficient is 0, then there is no linear relationship between the variables.
3) If the correlation coefficient is negative, then there is a negative linear relationship between the variables.
4) If the correlation coefficient is positive, then there is a positive linear relationship between the variables.