Weak-Interaction Processes Conserve Both Electric Charge and a Quantity Called $=+1$

Multiple Choice

Weak-interaction processes conserve both electric charge and a quantity called "lepton number." Electrons have lepton number $=+1$ , positrons have lepton number -1 , and nucleons have lepton number $=0$ . Study the weak interactions in this chapter.
-(a) What can you infer about the lepton number of the neutrino?

A) This quanton has lepton number $=+1$ .
B) This quanton has lepton number $=-1$ .
C) This quanton has lepton number $=0$ .
D) One cannot determine this quanton's lepton number from the processes we have studied.