单项选择题
在下面四个结构式中,哪个画有圈的质子有最大的屏蔽常数()
A.(1)B.(2)C.(3)D.(4)
A. B. C. D.
A.25.4%,39.4%,35.1% B.13.8%,43.3%,43.0% C.17.0%,53.3%,30.0% D.38.4%,29.1%,32.5%