You are not copy+pasting correctly, and not reporting back what the error message is. "Still no good" is not a useful diagnostic. But if you carefully use your mouse to copy+paste the commands above, and carefully copy+paste any errors back here, we might be able to help you.

"Unknown option to s" means you have something after (what sed thinks is) the final separator which is not a valid option for s/from/to/gp (here, "g" and "p" are options). In this case, it's simply because you still use slash as the separator, without escaping those slashes which are not separators. Change the separator to %, or escape the slashes as required.

Also, your command is partial; you are missing the "to" part \1$answer\2