Which of the Following Statements Is True Concerning ${ } ^ { 16 } \mathrm { O }$

Which of the following statements is true concerning ${ } ^ { 16 } \mathrm { O }$ and ${ } ^ { 17 } \mathrm { O }$ ?

A) They have the same number of neutrons.
B) They are isotopes.
C) They have the same relative atomic mass.
D) They have the same mass number.
E) They have different chemical properties.