Which of the Following Statements Are True? I

Which of the following statements are true? I.The number of protons in an element is the same for all neutral atoms of that element.
II) The number of electrons in an element is the same for all neutral atoms of that element.
III) The number of neutrons in an element is the same for all neutral atoms of that element.

A) I,II,and III are all true.
B) Only I and II are true.
C) Only II and III are true.
D) Only I and III are true.
E) I,II,and III are all false.