Computer Science

HTML stands for Hypertext Markup Language, which is the standard language used to create and design web pages. Option B correctly reflects this full form.

Ctrl + Y is the standard keyboard shortcut for the 'Redo' action, which reverses the last 'Undo' command in most software applications.

Input devices like keyboards and mice are used to enter or input information into a computer system, making option B the correct answer.

Twitter was launched in 2006, making option A the correct answer. The other years listed are incorrect for Twitter's launch date.

The Internet is commonly referred to as both "a network of networks" because it connects multiple smaller networks, and "the Net" as a popular shorthand. Therefore, option C, "Both," is correct.

CSS stands for Cascading Style Sheets, which is the correct and widely accepted full form used in web development for styling web pages.

The font size tool in many MS Office applications can be accessed quickly using the shortcut Ctrl + Shift + P, which opens the font size dialog box. The other options do not correspond to font size adjustment shortcuts.

The '@' symbol is used to separate the local part and the domain part of an email address, effectively dividing the email into two parts.

RAM stands for Random Access Memory, which is a type of computer memory that can be accessed randomly at any time, regardless of physical location in memory.

The welcome screen in most operating systems displays the names of all user accounts on the computer, allowing users to select their profile to log in. This matches option B, making it the correct answer.