Hi there!
The correct answer is A. HTML.
HTML stands for Hypertext Markup Language which is used in nearly all websites and web-based programs. HTML acts as a structure for a website giving you the text, page titles, text-boxes, etc... HTML is also used along with the languages of Javascript, CSS, C++, and others. DO NOT confuse languages like Javascript and the rest with Markup Languages because they are not the same! Javascript, for example, is what is used to make websites more user-friendly and interactive. When you use Brainly, for example, and you hover over someone's name or picture and that box pops up that is Javascript at work and not HTML or any other Markup Language.
-ASIAX Frequent Answerer
