How to Display Only Parent Category in Post Url Wordpress

Question

I'm New to WordPress and building an Multiple Choice Question Database Website. As you can see the post URL in Quite Long and Causing SEO Problems. I want to trim this url by only showing the parent category and post title in the link (ie mcqs). I'm using a Hierarchical style categories.
MCQS (Parent)
-10th Class MCQS (Child)
--10th Class Chemistry MCQS (Child)

CURRENT URL http://fgstudy.com/mcqs/10th-class-mcqs/10th-class-chemistry-mcqs/10th-class-chemistry-mcqs-water

URL I NEED http://fgstudy.com/mcqs/10th-class-chemistry-mcqs-water/

Answer 1

Simply Edit Post and Select MCQS (Category You Like) as the PRIMARY CATEGORY Update Post and DONE. View Image Here