Final answer:
Option a. Subscript text is smaller and appears below the baseline of the surrounding text, frequently used in mathematical and chemical notation.
Step-by-step explanation:
Text that appears slightly below the line of the other text in a document is called subscript. This formatting style is commonly used in mathematical and chemical formulas, such as H2O for water, where the '2' is written as a subscript. Subscript text is often smaller than the normal text and is typically used to denote variables, footnotes, or chemical compound numbers.
The text that appears slightly below the line of the other text in the document is subscript. Subscript is a formatting style that is used to represent smaller characters or symbols below the normal line of text. It is commonly used in mathematical equations or chemical formulas to denote a subscript.