Silpion

This plugin gives a possibility to manage Frequently Asked Questions as a custom post type. Site admin is able to add and edit questions and answers, assign them to categories and then display the output on any page using [faq] or [faq category={{category_id}}] on any WordPress page.
You can embeed the FAQ directly in your code using lcb_faq_display() function.

LCB FAQ

Displays questions with answers with FAQ category column.

Ravi Soni

expresstechsoftware

Sunny Soni

This plugin allows the customers to ask questions about each product in your store and admin to answer/update/delete them and add new questions from the backend product page. 
You can also drag and drop questions to change their order of appearance.
PLUGIN’S FEATURES: 
1. Avails logged-in customers to ask questions about each product. 
2. Avails Administrator and Shop Manager to moderate questions and give answers. 
3. Avails Administrator and Shop Manager to change the order of question-answer pair on front-end. 
4. Infinite AJAX loading on frontend, so your customers can view all questions without reloading the page. 
5. Enable/Disable paginations, change page size, update “Load More” button text and layout. 
6. Two question-answer layouts available for front-end: Normal and Accordion. 
7. Shortcode [display_qa_list] to display the list of questions and answers anywhere. If not used on a product page, include the product_id parameter to specify the product. 
8. Shortcode [qa_form] to display the question submission form for a product. If you are using it on a page other than the WooCommerce product page, include the product_id parameter to specify the ID of the product you want to associate the question with.
<h3>Configuration</h3>
No configuration needed! just install and it will start working from there, you can change the settings at any time though.

Product Questions & Answers for WooCommerce

Allows the customers to ask questions about products and admin to answer/moderate them.

LCB FAQ vs Product Questions & Answers for WooCommerce