Which of the Following Statements About the Modern Periodic Table

Which of the following statements about the modern periodic table in your text is incorrect?

A) The periodic table is arranged by increasing atomic mass.
B) The elements are arranged in rows and columns to emphasize periodic properties.
C) Elements in the same vertical column are called groups or families.
D) Each group has a Roman numeral and a letter associated with it.
E) A horizontal row of elements is called a period.