"Ridge" is a valid value for the CSS "border-style" property, so the statement is true.
The "border-style" property specifies the style of the border of an element, and "ridge" is one of the possible values that can be assigned to this property. The "ridge" value creates a border that appears to be raised and three-dimensional, with light edges at the top and left and dark edges at the bottom and right.
Other possible values for the "border-style" property include "solid", "dotted", "dashed", "double", "groove", "inset", "outset", "none", and "hidden".