Labels in Excel refer to text or special characters that are used for descriptive purposes in rows and columns, such as headings or titles. They provide context for the data but cannot be treated mathematically. The following points clarify the options:
Option (A): Labels can include text or special characters.
Option (B): Labels are used to describe rows or columns and help in understanding the data.
Option (C): Incorrect, as labels cannot be used for mathematical operations.
Option (D): Correct, as it combines both valid descriptions from (A) and (B).
Thus, the correct answer is \( \mathbf{(D)} \) (A) and (B) both.