Rank is defined as what?

• A. A line, which is only one element in depth
• B. A column
• C. A file
• D. A unit

Answer: (A)

Rank represents a horizontal grouping of elements—a line that runs left to right. Think of a grid or board where you line things up across one row; that row is a single line that’s only one element thick in the depth direction, so it’s described as a line rather than a column or a flat surface. On a chessboard, for example, the ranks are the horizontal rows, each spanning from one edge to the other.

This is why the description “a line, which is only one element in depth” fits best: it captures the idea of a single horizontal row with minimal depth. A column is the vertical alternative, a file refers to a vertical alignment on a board, and a unit would be just a single element, not a line.