[单选题]
In all three types of radiodt t7n,mw6fb (rbzd ,6actcyv7qun/ g/.y6bn g tt.3 gy;vive decay, what value is conserved in addition to electric charge, enecy.g/yq u t3 n7 /.gbngyt6vv;rgy, and momentum?
A. atomic number
B. neutron number
C. nucleon number
D. none of the given answers
