r how to remove trendlines from model diagnostic plot ()

I am running a simple linear regression model

lm.SR <- lm(sr ~ pop15 + pop75 + dpi + ddpi, data = LifeCycleSavings)

This is my diagnostic plot using the default plot() function

 plot(lm.SR)

I like to remove the red trend line from the diagnostic plots. Not sure how to do that. Any help is highly appreciated. Thanks.

>Solution :

Try:

plot(lm.SR, add.smooth = FALSE)

When you plot an object of class lm you are using plot.lm, so you can use ?plot.lm to see the available options.