The correct choice is ASCII, which stands for American Standard Code for Information Interchange. It is a character encoding scheme that represents text in computers and communication equipment that use text. ASCII uses a 7-bit binary number to encode characters, which allows for 128 different characters, including letters, digits, punctuation marks, and control characters.
Most microcomputers predominantly use ASCII because it is simple, efficient, and sufficient for handling basic text data in English and other Western languages. Additionally, ASCII's early adoption in computing has led to its widespread use and support across various software and hardware platforms, making it a foundational coding scheme in the world of microcomputers.
The other options, while relevant in different contexts, are not as commonly used in microcomputers. EBCDIC (Extended Binary Coded Decimal Interchange Code) is primarily used in IBM mainframe and midrange computer environments. UTF-8 and Unicode are more advanced character encoding schemes that can support a much larger range of characters and symbols, accommodating many languages and special characters. However, these are typically used in applications that require multilingual support and are not exclusively necessary for the basic operation of most microcomputers. ASCII remains the standard for basic text representation in many scenarios.