Welcome to the site :)
Since the input/output is fixed then a scripting language like AIML would work for that.
You would be doing things like this :
<category>
<pattern>HOW TALL ARE YOU</pattern>
<template>Oh about 8 feet !</template>
</category>
Here's something to read on AIML : Learn AIML (https://www.tutorialspoint.com/aiml/index.htm)
And a more general article we have here : How To Create Your Own Customised Chatbot For Beginners - Chatbots 101 (http://aidreams.co.uk/forum/index.php?page=How_To_Create_Your_Own_Customised_Chatbot_For_Beginners_-_Chatbots_101)
Part two of the latter (A Web-Based Chatbot - Pandorabots) you might want to read first as that deals with a service that will run AIML bots.