input instead radios

Hi

I would like to see input for user entering text, instead radios. (for Phrase captcha and Unrelated word captcha)
Mainly for Phrase captcha it would be much better solution because user have to enter text (answer) for phrase.
If the spam bot is trying to answer, there is always chance 1:x where x is number of options, that the spam answer correctly.
If there would be need to type answer - it will be much more better
Another option for better working is that there could be more phrases with answers, and the system choose random from them.

thanks
Igor