[单选题]
The binding energy p x428gz,uxq ;n rx3ogd*hvx b,o 15z,fnxz(yng bw 4l8)x,c lier nucleon
A. increases steadily as we go to heavier elements.
B. decreases steadily as we go to heavier elements.
C. is approximately constant throughout the periodic table, except for very light nuclei.
D. has a maximum near iron in the periodic table.