A chemist found one atom with 9 protons,8 neutrons and 7 electrons.Another atom has 8 protons,9 neutrons and 10 electrons.Which of the following statements is correct?

A)Both atoms have the same mass number.
B)Both atoms have -2 electrical charge.
C)Both atoms are isotopes of the same element.
D)Both atoms are chemically non-reactive and would not interact with other atoms.
E)Both atoms have fulfilled the octet rulE.