To answer this question, you need to understand how to add client-side script to C# code.
Let's go through each option to understand why it is correct or incorrect:
Option A) AddJavaScript - This option is incorrect because there is no built-in method named "AddJavaScript" in C# for adding client-side script.
Option B) RegisterClientScript - This option is correct because the "RegisterClientScript" method is used in C# to add client-side script to the page.
Option C) AddClientScript - This option is incorrect because there is no built-in method named "AddClientScript" in C# for adding client-side script.
Option D) RegisterJavascript - This option is incorrect because the correct method name is "RegisterClientScript", not "RegisterJavascript".
The correct answer is B) RegisterClientScript. This option is correct because it is the method used in C# for adding client-side script to the page.