Dealing with rudeness in kids

[Gutterboot]

Is it better to
a) ignore and raise when they’re calm/in better form
b) address immediately eg “speak nicely” “if you can’t say anything nice, don’t say anything at all” “I won’t tolerate rudeness” “ Don’t speak to me so rudely” or different words (if so, what?)
c) something else (if so, what?)

Thanks in advance for your thoughts

They say a) is the best strategy but personally doesn’t work for me cause I don’t tolerate rudeness… Also they say no ‘don’ts’ so instead of saying don’t be rude you say it’s ok to feel angry/frustrated/disappointed but it’s not ok to speak to me/sibling this way … not an expert but been reading a lot :)