The Reaction $\mu$ ^- $\to$ E^- $\bar{v}_{\mathrm{e}}$ $\bar{v}_{\mu}$ Conserves
A)muon Lepton Number but Not Electron Lepton Number

Multiple Choice

The reaction $\mu$ ^- $\to$ e^- + $\bar{v}_{\mathrm{e}}$ + $\bar{v}_{\mu}$ conserves

A) muon lepton number but not electron lepton number.
B) electron lepton number but not muon lepton number.
C) neither muon lepton nor electron lepton number.
D) both muon and electron lepton numbers.
E) None of these is correct.