What is the main advantage of using a WYSIWYG (“what you see is what you get”) editor when constructing a website? Only one programming language is required.
Websites may have more professional construction.
Knowledge of HTML is not required.
Website templates are not necessary.

The answer to this question is given below in the explanation section.

Explanation:

The correct answer among the given options to this question is:

Knowledge of HTML is not required.

Because when you are constructing a website using WYSIWYG (“what you see is what you get”) editor, then you don't need the knowledge of HTML. Because, when you use WYSIWYG editor to insert button, table, images, text, paragraph, etc. It will automatically insert HTML code behind the page. For example, you can insert a form and a submit button using drag and drop with the help of WYSIWYG (“what you see is what you get”)  editor, for this purpose, you don't need exact knowledge of HTML. WYSIWYG (“what you see is what you get”)  automatically inserts the HTML for the form and button on a website page.

While other options are not correct because:

Using the WYSIWYG (“what you see is what you get”)  editor, you can use different programming languages in your website, such as VB.net, Asp.Net, C#, Javascript, Bootstrap, etc. It is not necessarily that you may have more professional construction and in WYSIWYG (“what you see is what you get”)   website templates are mostly used and modified using WYSIWYG editor.