Masses of two isobars 29Cu⁶⁴ and 30Zn⁶⁴ are 63.9298 น be concluded from this and 63.9292 น. It can

(1) Both isobars are stable
(2) Zn64 is radioactive decaying to Cu64 through ẞ decay
(3) Cu64 is radioactive decaying to Zn64 through y decay