I don't want to come as overbearing but that option is NOT CAPTCHA. I think its important to identify properly because bots could hack your q/a pretty easily. Even if it was random from 2 choices it would be more of CAPTCHA than what this plugin has.
I run SweetCAPTCHA on my sites. Please look into it. If you were to give me a "Enter code for your CAPTCHA program" I could then let it run my CAPTCHA and be more confident I won't get a spambot.