[单选题]
If an atom's atomic number is give.9ka,n 7uxyl-dm ylo;n by ze8gfjqzl1+il83ar,:: zgo x Z, its atomic mass by A, and its neutron number by N, which of teqgg:ix88lzz1 +3f:l ajo,z rhe following is correct?
A. N = A + Z
B. N = Z - A
C. N = A - Z
D. none of the given answers
