下列粒子中，能决定元素种类的是请选择DCBA'T0T,X6B4q-F*p4V0b4i;^,U3~;_:E5}*z+T4Y9E8Y5U
A．最外层电子数;^,U3~;_:E5}*z+T4Y9E8Y5U
B．质子数;^,U3~;_:E5}*z+T4Y9E8Y5U
C．电子数;^,U3~;_:E5}*z+T4Y9E8Y5U
D．中子数;^,U3~;_:E5}*z+T4Y9E8Y5U