[单选题]
In a nuclear reaction, wfoe0e y7.ah5yoee2h; hat value is conserved in add5kh y,/dprw ,cw,5i boition to electric charge, ebwyp w5/k5odi, ch,r ,nergy, and momentum?
A. atomic number
B. neutron number
C. nucleon number
D. none of the given answers
