[单选题]
The Feynman diagram shows two elec 9m vut/5haxj6c4dkt 7mk+, qdtroz;v(e ufn9j,,uo) y qzns approaching each other, interacting, and then leaving each other. What particle is beinu9 zezny ;,(qfou,jv)g exchanged during the interaction?
A. pion
B. virtual photon
C. neutrino
D. $W$ particle
