Erro "While executing gem ... (OptionParser::AmbiguousOption) ambiguous option: --no"

I am new to programming and I am really interested in learning ruby on rails. So, i attempted at installing rails on my macbook with the following command: gem install rails --no-ri --no -rdoc

However, I got the following:

Erro "While executing gem ... (OptionParser::AmbiguousOption) ambiguous option: --no"

So, my question is who do i resolve the cause of the error.

Thanks