What is defined as a group of related data elements arranged either in rows or columns?

The correct answer is a data table. A data table is specifically designed to organize and represent data in a structured format using rows and columns. Each row typically represents a unique record or entry, while each column represents a specific attribute or characteristic of that record. This organization allows for easy access, retrieval, and analysis of the data contained within the table.

A matrix, while it also consists of elements arranged in rows and columns, is more of a mathematical structure used primarily in mathematical operations rather than for data organization in typical data contexts. A one-dimensional array represents a single linear sequence of elements, lacking the two-dimensional structure of rows and columns found in data tables. A set refers to an unordered collection of unique items, which does not have the structure of rows and columns either. Thus, the most suitable term to describe a group of related data elements organized this way is indeed a data table.