How to Optimize Your Content for Google’s Rich Answer Box

Identify Queries – Go to adwords keyword planner or by Google instant.

Directly Answer the Question

Consider User Experience – If you are creating content around a query best answered in list form, then make sure you use either ordered list tags (<ol>) or unordered list tags (<ul>) to highlight to Google what form the content is in.

Use Entities in Your Content 

Include SEO Best Practices/Schema Markup – There are many different types of markup that will produce Knowledge Graph-driven results, and you can find all the different schema options at Schema.org and Schema-Creator.org.

Read here – https://www.searchenginejournal.com/optimize-content-googles-rich-answer-box/154424/