[单选题]
In a nuclear reaction9g +qt2ge;ag uk8x9) mjuo,ht, what value is conserved in addition rs ;/a7 nawfppp2+00pif8od u to electric charge, energy, and momw ff2;podn78ua/ ar0 0 ipp+psentum?
A. atomic number
B. neutron number
C. nucleon number
D. none of the given answers
