Which equation shows the change in the quark composition of a nucleus and the emission of leptons during $\beta^{+}$ decay?
- Adown $\rightarrow$ up + positron + electron neutrino
- Bdown $\rightarrow$ up + positron + electron antineutrino
- Cup $\rightarrow$ down + positron + electron neutrino
- Dup $\rightarrow$ down + positron + electron antineutrino