Which of the Following Statements Is Not True About the Constant

Which of the following statements is not true about the constant standard deviation condition of the linear regression model?

A) A residual plot can highlight the existence of a nonconstant standard deviation even when it is hard to see in the original scatterplot
B) A constant standard deviation means that the vertical spread of the y-values about the line is the same across the entire line.
C) A fan shape in a residual plot indicates that the constant standard deviation condition does not hold.
D) All of the above are true about the constant standard condition.