Which of the following correctly differentiates ASCII from Unicode?

The chosen answer highlights a fundamental aspect of the encoding systems: ASCII and Unicode differ significantly in their bit usage, which impacts how many characters they can represent. ASCII utilizes a 7-bit encoding scheme, allowing for 128 unique character representations, which covers basic English characters, digits, and some control characters. In contrast, Unicode is designed to support a much broader range of characters across many languages and symbols, using a variable-length encoding system that can utilize 8 bits, 16 bits, or even 32 bits. This allows Unicode to encompass tens of thousands of characters from various global scripts, making it a far more comprehensive system for text representation than ASCII.

This differentiation underscores the evolution from a limited character set to a universal encoding standard that accommodates the needs of a globalized digital communication environment. Thus, the answer accurately reflects the distinct capabilities and applications of both ASCII and Unicode in the realm of computer science.